Voices in Your Head is a student-run a cappella group from the University of Chicago who aim to "push the bounds of contemporary a cappella." Founded in 1998, the group has consisted of both undergrad
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 Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x85f6929d6023da97bfa0388562885b41536ba36e5df3559314ce39892502a440. Chain 2 (Bitcoin): anchored in block 953407 (2026-06-12T19:24:56Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/0e4069b6-14d0-43b9-aef7-87ed84a33192.json and https://artists.proofprofile.net/proofs/artist/0e4069b6-14d0-43b9-aef7-87ed84a33192.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).
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 Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xb275ed5514957dbb63fe5db29f7d4c2460e75a0b57fb3bcbd43821fbc966749e. Chain 2 (Bitcoin): anchored in block 958943 (2026-07-21T00:27:37Z), 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/USE830901059.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x4027c738c770ce3e38cbcdd8936565b23535c0800d2f1c44a32dc5e4bf660f27. Chain 2 (Bitcoin): anchored in block 958060 (2026-07-14T20:39:42Z), 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/USE830924038.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe9ebec593b196818e1bdada8e597323d203b2cfb1ab19a75ae0267afebb20ab6. Chain 2 (Bitcoin): anchored in block 958157 (2026-07-15T15:53:04Z), 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/USE830941840.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x44a819847fd5b3c790e38172f2a18ecbe9ea923d0050947f419e7861f96da0cc. Chain 2 (Bitcoin): anchored in block 958971 (2026-07-21T05:04:56Z), 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/USE831529349.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa431d2fcfd00f9254d8e64e56e55bf0dd6c7437600cf97dbaa0dafdc4ebb32c4. Chain 2 (Bitcoin): anchored in block 959096 (2026-07-22T06:49:08Z), 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/USE831573653.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xd77f7be77d19c098e4d30e7769995c19bfaae21896da8611866b1ed394892256. Chain 2 (Bitcoin): anchored in block 958695 (2026-07-19T07:37:00Z), 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/USE831573658.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x745e5529df7b70245202c87599b300a22802cb187160562774f2fcd80ebea482. Chain 2 (Bitcoin): anchored in block 958959 (2026-07-21T03:51:22Z), 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/USE831573661.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa4e1ef53fd6e858ea57ce721709dde05f3d6c45712e399c839a4607711b24505. Chain 2 (Bitcoin): anchored in block 958544 (2026-07-18T12:14:37Z), 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/QZ22B2054854.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x2a372c177fafadc1f25150406f3494535bd3c8403be454a10d32430f6f042898. Chain 2 (Bitcoin): anchored in block 958251 (2026-07-16T06:29:25Z), 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/QZ22B2054855.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xf57c9e312a530a38cd441c2449f5bcb2a2a1e76cc1d0ed4bd8a7b205129e4c7d. Chain 2 (Bitcoin): anchored in block 958600 (2026-07-18T19:24:05Z), 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/QZ22B2054856.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x0385ebf9b411d29f8a71ca7e5a3692ff9edaf93cbe1e14ada4e146bd05bb766c. Chain 2 (Bitcoin): anchored in block 958876 (2026-07-20T12:15:48Z), 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/QZ22B2054857.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x8bad8a6397c76a4a0bd733fa6f181e11656d6d7c878b322c9ad4cdcb9fb4860b. Chain 2 (Bitcoin): anchored in block 959087 (2026-07-22T02:05:55Z), 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/QZ22B2054860.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xe8886c51e1ee59ae2fd81d56d44ade21ff8935e24cd18931cf885ed79c3dbacf. Chain 2 (Bitcoin): anchored in block 959023 (2026-07-21T17:14:10Z), 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/QZGWW2089031.
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xbb4ee1454fa2567cdc909c2f6d5f9fca9a728771d04d38473deb6d2859ce0536. Chain 2 (Bitcoin): anchored in block 956725 (2026-07-05T01:12:41Z), 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/QZPJ32306262.
Voices Only 2012 College A Cappella, Volume One
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0x9739aac36da3e44fd4466d2c93c7b683fe68e0d91a6ed6236c34c58ce9c04f30. Chain 2 (Bitcoin): anchored in block 956304 (2026-07-02T03:55:08Z), 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/TCABI1211372.