The Signum Quartet is a string quartet based in Bremen, Germany. Founded in 1994, it has been playing in the current formation since 2016.Florian Donderer appointed Signum Quartet first violinist. Web
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x52f2ce9ba87ada182c84a39fecf68daf1d943840dbe15b8a19e65d3e7d33441a. Chain 2 (Bitcoin): anchored in block 953697 (2026-06-14T21:49:28Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/6f0316e6-d6ce-47b1-bf0c-5723cf9042bf.json and https://artists.proofprofile.net/proofs/artist/6f0316e6-d6ce-47b1-bf0c-5723cf9042bf.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
Viola Concerto: I. Pizzicato, Molto rubato - Più mosso
Symphonieorchester des Bayerischen Rundfunks
1. Confirm isrcCode identifies the recording in the pre-2022 source corpus and cc-db-prod record 2. GET OTSVerificationAPI → server-side canonical-record, hash, and attestation checks must pass 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Confirm CopyrightID is the CopyrightChains transaction hash 5. If all match: the cc-db-prod record is independently anchored on Bitcoin at OTSTimestamp
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9c8b106c1cf4079cb22c4c83245d963b500dde5efabd62c9fbf8f8298c89a216. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/FR7JM1756010.
Der Tod und das Mädchen, Op. 7 No. 3, D. 531 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x685e5ed7aaf893a4ac7e257adc1f66bc1e025a5d5c0c8a7c28320efe30494868. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422006601.
Piano Quintet in A Major, Op. 114, D. 667 "Die Forelle": II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5192efc50e439b824a398b5709212cfa9decedd5b65a2bb8fb53dfae61158485. Chain 2 (Bitcoin): anchored in block 956312 (2026-07-02T05:09:12Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE420800402.
Piano Trio No. 2 in E-Flat Major, Op. 100, D. 929: III. Scherzando. Allegro moderato
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf61356b6c90ed694de3409257aea2b36ddf7f2dcab0bd2ad0da169533b44e687. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE420603107.
Du bist die Ruh, Op. 59 No. 3, D. 776 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf97d60e4edbdec34095874ec50b1700d8e8d7d2da77c3212936db5a48830b7d1. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421701514.
Violin Sonata in D Major, Op. 137 No. 1, D. 384: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x846cb11fe5bfb733de57ab07473458ac6cc6f4529bca73bfbea7c9415a4b360d. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE420900102.
Erlkönig, Op. 1, D. 328 (Arr. M. Reger for Voice & Orchestra)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x00ef83f96d9a589f0528df4f3951692a6cf76872ec9995581391603bddc06fd7. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421401002.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd7f6e54e191816d75d6b47749ada8c4337055d2bafe5e4fb884207cbd1d1e06a. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421902517.
Pictures at an Exhibition: Promenade III
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb5b3fff06086477418106f778d3f6927da2b9a804e3eaecab5ec7062471451eb. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE420900910.
Violin Concerto No. 3 in G Major, K. 216: II. Adagio
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x282d112da9536ef6c5bdbef1c3227e910d8626ed43dba4ff7deded10b0635da1. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421301302.
Piano Sonata No. 25 in G Major, Op. 79: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd9f6a87714a15725bc31e760ead0b412224b2864bf4e19afa2d39b2af7c18c6b. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE420801502.
Piano Concerto No. 1 in G Minor, Op. 25, MWV O 7: II. Andante
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x283c57743896bda85c732c02da6e3b80faee66317ffc9690c603ee5b1a6591a3. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421000102.
Symphonic Metamorphosis After Themes by Carl Maria von Weber: III. Andantino
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x11c3085dfb04ca8d941e97671987351fdce13c61c81cf27ba4eeffcd001185cc. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421701403.
Waldszenen, Op. 82: No. 3, Einsame Blumen
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xefed7966a871fbc26b8c22dd7ab38ba0047254d8a5e2f831be2b9e83ea7eaa1e. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421100903.
Piano Sonata No. 31 in A-Flat Major, Op. 110: III. Adagio ma non troppo. Arioso dolente
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x7ddd556d836a74085b756de62378b232713c3cb2ee0079907db0ca5ada357457. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421101406.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x86e714c6d82435bf096399f2d5554eb0cbaa2d24155cdbc76d2af0980f94e1b9. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421402306.
Wandrers Nachtlied, Op. 96 No. 3, D. 768 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x94426779aaa088400c25f4a67288938096a53a454f97ff23003abda6cd42fcda. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421701509.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0c7fa1ddcd46b84c0fcb7582aa145d7b347476c34325ec228ad599c7aaa87b27. Chain 2 (Bitcoin): anchored in block 957120 (2026-07-08T03:22:41Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421404918.
Abendstern, D. 806 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e4ff01f3bbad2f62c7c9006cfcd3750ee8c030873cff569e764eced6dcf605f. Chain 2 (Bitcoin): anchored in block 957124 (2026-07-08T03:53:27Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422005308.
String Quartet No. 16 in F Major, Op. 135: III. Lento assai, cantante e tranquillo (Arr. M. Mussorgsky for Piano)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xee127bd22e5e7c716eb7cb581a821c5f5036789ffe9165b30b459efe311a08b8. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421903806.
Ins stille Land, D. 403 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x19e243b59fa55fe4138d6bb35b771a22ffc72b4e92f6c80159a80601a399438e. Chain 2 (Bitcoin): anchored in block 957122 (2026-07-08T03:39:04Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422005301.
Frühlingsglaube, D. 686 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x12894c731ee0ee6fb1440a2893809d6b5493fd87ceb079890f375f378cff6fb4. Chain 2 (Bitcoin): anchored in block 953528 (2026-06-13T15:41:10Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422005302.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x5e4ff01f3bbad2f62c7c9006cfcd3750ee8c030873cff569e764eced6dcf605f. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422005308.
Auf dem Wasser zu singen, Op. 72, D. 774 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4926bdd95d6bf52d0a33f1d5edc24e56a156944c9fd49aeb9eaa7780e7a64de9. Chain 2 (Bitcoin): anchored in block 957118 (2026-07-08T03:20:19Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422005309.
Schwanengesang, Op. 23 No. 3, D. 744 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf9c6895753e92bef68c97acfd24b8e5e59763f57a9d54c6ae31aff97bd7f8b97. Chain 2 (Bitcoin): anchored in block 957145 (2026-07-08T08:56:20Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE422005315.
Beethoven - Quatuors à cordes Opus 130 & 133
Wandrers Nachtlied II, Op. 96 No. 3, D. 768 (Arr. X. van Dijk for String Quartet)
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x94426779aaa088400c25f4a67288938096a53a454f97ff23003abda6cd42fcda. Chain 2 (Bitcoin): anchored in block 956302 (2026-07-02T03:30:09Z), registered by our registry partner. The server verifies the private canonical record against OTSHash without exposing internal provider keys. Confirm the public ISRC, CopyrightID, and Bitcoin evidence via https://artists.proofprofile.net/api/v1/bot/ots/verify/track/NLE421701509.
LiederZwerge - Musik aus dem Baby-Konzert