A Nashville songwriter walks into a co-write Tuesday morning with three half-finished ideas she has been working on for months. One is a verse melody and lyric she has been refining since a long drive in February. Another is a chord progression and topline she demoed alone in her studio in March. The third is a song title and hook idea she has been carrying around since last autumn.
The session goes well. By Friday a finished demo exists. Two months later, the song is cut by a major-label artist. Six months after that, it is the lead single from a number-one album. The cue sheet is filed with three co-writer credits, each receiving a third of the songwriter share.
She knows the verse melody was hers. She knows the chord progression underneath the chorus was hers. She knows the title was hers. Her co-writers remember it differently. Her publisher accepts the cue sheet as filed.
There is nothing acrimonious here. Nobody is acting in bad faith. The co-writers remember the room differently, and there is no objective record of who brought what. Three months of work she did before the session became, by the equal-split convention, a one-third share on a song paying tens of thousands of pounds a year.
This scenario is not exceptional. It is structurally typical of how co-writes work, and it is the principal reason songwriters quietly carry resentment that surfaces years later. The work brought into a session — the pre-existing ideas, melodies, lyrics, progressions — is rarely documented in a form that survives the room. The session itself produces a unified artefact, the finished song, in which contributions become difficult to disentangle.
Provlyn was built specifically for the question this scenario raises. Before the session, each songwriter can deposit the work they are bringing into the room — voice memos, MIDI files, lyric drafts, chord charts, whatever form the pre-existing ideas take — into a private vault. Each deposit is hashed, timestamped by an accredited Trust Service Provider under RFC 3161 qualified under eIDAS Article 41, and anchored on the Bitcoin blockchain. The pre-session timeline becomes evidenced, in a form that no co-writer or publisher can later dispute.
A co-write is a creative collaboration with two or more songwriters in a room, often for the first time, working through a fixed window — sometimes a single day, sometimes a two- or three-day block. The objective is a finished song, ideally pitchable to artists or producers within a few weeks.
The convention in most professional songwriting markets is an equal split of writer shares, regardless of who contributed which specific element. This is not because contributions are equal in reality. It is because contributions are almost impossible to measure mid-session, and the equal-split convention removes friction that would otherwise prevent the song from being finished. Everyone signs the split sheet. Everyone moves on.
The implicit understanding is that, over time, everyone benefits from the same convention applied to other co-writes they participate in. The songwriter who contributed less to today's song will contribute more to next month's, and the splits will balance out across a career.
That implicit understanding works tolerably well within a small, repeating community of writers who all know each other and have a shared history. It works less well across the wider co-writing market — sessions where writers meet for the first time, where one or more participants brings substantially more pre-existing material than others, or where the resulting song goes on to be a major commercial success in which the stakes of the original split suddenly become significant.
In a co-write dispute, the question of who contributed what is almost never resolved by reference to objective evidence, because objective evidence rarely exists.
Memory is unreliable, particularly for events from months or years earlier. Each songwriter believes their own recollection of the room. The other writers believe theirs. There is no neutral party who watched the session and can adjudicate. Audio recordings of the session are usually not preserved, and even when they are, they typically begin once the song has started taking shape — after the moment when pre-existing material was introduced.
Voice memos on the original songwriter's phone might exist, dated to months before the session. Whether they are admissible, and whether their dates are credible, depends on the phone's metadata, which is editable and contested. Email threads might show the songwriter sending a rough idea to a collaborator before the session, but only if such an email exists, and only if it identifiably contains the element later in dispute.
In practice, what songwriters are left with is the cue sheet — the formal document filed with performing rights organisations declaring the writer shares — and whatever publishing agreements followed. Once the cue sheet is filed and accepted, challenging it later requires evidence the songwriter typically does not have.
Prior proof of authorship — established before the session begins — is what changes this position.
Establishing prior proof of song authorship does not mean documenting every note or lyric in advance. It means creating a verifiable record of the specific pre-existing material being brought into a particular session, before the session takes place.
A voice memo of the verse melody, recorded in February. A MIDI export of the chord progression, drafted in March. A typed lyric draft of the hook line, written last autumn. Each of these is a digital file. Each can be deposited in a Provlyn vault before the songwriter walks into the room on Tuesday morning.
The deposit produces a fingerprint that is cryptographically tied to that exact file. The timestamp confirms when the deposit was made. The blockchain anchor makes the record permanent. The contents of the files remain private — only the songwriter sees what is in them. What becomes public, if and when it is needed, is the fact that those specific files existed in those specific forms before the session.
If a dispute later arises, the songwriter can produce the original files, demonstrate that their hashes match the certificates in the vault, and establish, to a court or to a publishing tribunal, that the verse melody, the chord progression, and the hook line all pre-dated the co-write by months. The cue sheet may still need to be re-negotiated. The publishing agreement may still need to be revisited. But the conversation now begins from evidence, not from competing memory.
Provlyn was built for this kind of routine deposit. A songwriter can record a voice memo on a phone, export a MIDI file from their DAW, or type a lyric draft into a notes app, and have it deposited in a Provlyn vault in under a minute. What Provlyn does at deposit — in order:
SHA-256 hash generated — a unique cryptographic fingerprint of the exact file. Change a single byte and the fingerprint changes entirely. The fingerprint cannot be reverse-engineered to reveal the file's contents. The file itself remains private, under the songwriter's control.
RFC 3161 timestamp applied — the fingerprint is timestamped by an accredited Trust Service Provider operating under the RFC 3161 standard, creating a cryptographically signed record of the exact moment.
eIDAS Article 41 qualification — the timestamp is qualified by an accredited Qualified Trust Service Provider (QTSP). The vault certificate carries a legal presumption of accuracy in EU member states and is treated as strong electronic evidence under UK law.
Bitcoin blockchain anchoring — the fingerprint is anchored on the Bitcoin blockchain through the OpenTimestamps protocol, creating a permanent public record that does not depend on Provlyn's continued operation.
Vault certificate issued — a downloadable PDF listing the file, its fingerprint, the qualified eIDAS timestamp, and the blockchain anchor. Admissible electronic evidence in UK and EU jurisdictions, independently verifiable by any court, regulator, or counterparty using public tools.
Used as routine practice, this creates a continuously building portfolio of pre-existing songwriting material, each piece independently dated and verifiable. Walking into any co-write with that portfolio behind her, the songwriter is no longer relying on memory or goodwill. She is relying on a record that pre-dates the room.
A fuller technical walkthrough of the deposit and verification process is at www.provlyn.com/how-it-works.
Songwriters who hear about prior proof of authorship sometimes worry that bringing it into a co-write would damage the trust that productive sessions depend on. The opposite is true. A vault deposit made before the session never needs to be mentioned in the room. It exists quietly in the background, available only if it is ever needed.
What it does change is the songwriter's underlying position. She walks in knowing that, regardless of how the room remembers things in three years' time, her contributions are documented. That confidence — quiet, unspoken, evidenced — is what makes it possible to be openly generous in the session itself.
Establish prior proof of authorship for your music
Provlyn provides cryptographic prior proof of ownership for any digital artefact. Each deposit is hashed with SHA-256, timestamped by an accredited Trust Service Provider under RFC 3161, qualified under eIDAS Article 41, and anchored on the Bitcoin blockchain. The vault certificate carries a legal presumption of accuracy under the EU eIDAS Regulation, is admissible evidence in UK and EU jurisdictions, and remains valid permanently, independently of Provlyn's continued operation. Start your free 7-day trial at www.provlyn.com. No credit card required.
This post provides general information about the role of cryptographic evidence. It is not legal advice. For advice on a specific matter, consult a qualified lawyer in your jurisdiction.
Related Reading
How to Prove You Created Something: A Practical Guide for Anyone Who Makes Original Work
Sending a Pre-Release Track: How to Prove Who Received a File and When
The $1.5 Billion Question: What the Anthropic Settlement Reveals About Prior Proof of Ownership
Blockchain-anchored timestamps and court-admissible certificates. Prove it. Permanently.
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