Remendo

What it does

Given an outgoing record and an incoming one, Remendo makes four decisions and then composes original instrumental music to carry the passage between them. The output is new music written for that pair. It is not assembled from either recording — no audio is cut, sampled or looped out of the inputs.

The four decisions

Everything the model composes follows from these, in this order. Each is derived from measurement rather than set by a rule of thumb.

Exit

The last real rest inside the outgoing record's final window. Never mid-phrase — the model looks for where the band actually drops, not where the clock says to cut.

Arrival

Not the incoming record's first sound, but where its low end lands and holds. An intro that is loud with no bass under it is entered at the drop, not at zero.

Length

Derived from how alike the two records measure, in bars rather than seconds, so the passage is musical rather than a fixed duration.

Instruction

What the passage has to do, written in the vocabulary a band would use — attacca, morendo, deciso — and handed to the composition step as its brief.

What it measures

Envelope

20 buckets per second, min and max per bucket

Similarity

cosine distance over a 16-bin energy histogram

Exit window

the final 20 seconds of the outgoing record

Arrival hold

1.5 seconds sustained above the median

How long a bridge runs

Length is a function of how alike the two records measure, and it is counted in bars rather than seconds so the passage stays musical. Close relatives need a bar or two; strangers need introducing.

Inputs and outputs

Model ID

remendo-2.1

Takes

2 recordings

Formats

MP3, AAC, WAV, FLAC

Size

40 MB per record

Returns

Original instrumental music, plus the four decisions that produced it

Intended use

Joining two recordings you have the rights to, in a set, a mix, a broadcast or a piece of video. Remendo is built for the moment between two records and is not a general music generator — asked for anything else, it will still try to write a transition.

Out of scope

• Reproducing, extending or imitating a specific artist, recording or voice. The model writes instrumental passages and is not built to sound like anyone.
• Standing in for clearance. A bridge sits between two existing works by design; whether you may release what you make with it is a question about your rights in those works, not about the model.
• Mastering, stem separation, key or tempo correction of the records themselves.
• Vocals. Remendo writes instrumental music only.

Training data

Licensed and public-domain material only. We do not train on anything uploaded to Seam Engine. A record you bring in is used to serve you and for nothing else — it is measured, it conditions the composition written for you, and it is deleted when you delete it.

Limitations

Stated plainly, because a model card that only lists strengths is an advertisement.

• The change is audible. The claim is not that you cannot hear the record change — you will. The claim is that you should not hear a join.
• A bridge resembles both records by design. It is written to leave in the character of the first and arrive in the character of the second. We do not assess whether a given bridge is substantially similar to any existing work, and we cannot warrant that it is not.
• Measurement degrades on difficult material. Exit detection depends on the outgoing record actually having a rest in its final window; a record that ends cold, or fades under a crowd, gives the model nothing to find. Arrival detection depends on a low end to land on.
• Tempo and key are measured, not negotiated. Two records far apart in both get a longer bridge, not a better one. There are pairs no passage rescues.
• The examples are hand-picked. Twenty-two front-page pairs play audio rendered by Remendo, each chosen by ear as the best of several renders of that pair, so they show the model at its best rather than its average. The other pair has no audio yet, and we say so rather than staging it.

Availability

Remendo 2.1 is in rehearsal. Access is by invitation, there is no public API, and there is no pricing — we would rather say that than invent a number. If you want in, there is a waitlist.

Reporting a problem

A transition that lands badly is useful to us — write to hello@seamengine.com with the pair and what went wrong. Rights and copyright questions go to legal@seamengine.com, and the process is on the copyright page.