Music Composer – MIDI Annotation Project

Twine; United States; On-site; USD 60,000 - 90,000; Full time

Job summary

Twine seeks experienced musicians, producers, and audio engineers for a music annotation project in the United States. You will create 20 recordings (3–4 minutes each) with separate MIDI/JSON annotation tracks for every instrument, ensuring precise onset/offset timing.

Deliverables include lossless WAV/FLAC files and annotated instrument data, with clear tier and capture method labeling. Proficiency in Logic Pro, Ableton Live, or Pro Tools is required, as is the ability to work with rights for

Qualifications

• Experience as musician, producer, composer, or audio engineer.
• Proficiency with DAWs (Logic Pro, Ableton, Pro Tools).
• Rights to supplied material for AI training and commercial use.

Responsibilities

• Contribute real music recordings 3–4 minutes long with note-level MIDI annotations.
• Provide separate annotation tracks for every instrument with onset/offset and timing accuracy 10–20 ms.
• Deliver 20 recordings across Standard and Enhanced tiers with lossless audio and per-instrument annotation files.
• Clearly indicate tier and capture method for each instrument track.

Skills

Musician

Producer

Audio Engineer

DAW Proficiency

Attention to Detail

Tools

Logic Pro

Ableton Live

Pro Tools

Job description

This role involves contributing real music recordings paired with detailed note-level MIDI annotations for an AI training dataset. You will supply either existing or newly created tracks, ensuring each recording is 3 to 4 minutes long and accompanied by a separate annotation track for every instrument. Each note must be annotated with instrument, pitch, onset, and offset, with timing accuracy within 10 to 20 ms. The preferred workflow is capturing audio and MIDI simultaneously in your DAW, but existing multitrack archives or manual annotation are also accepted. Genres beyond pop, rock, and Western classical are especially valuable, and a diverse range of instrumentation is encouraged. Full guidance on format and labeling will be provided before you begin.

Deliverables

• Provide 20 unique music recordings, each 3–4 minutes in length, split across two quality tiers (Standard and Enhanced note-off accuracy).
• For each recording, deliver one lossless audio file (WAV or FLAC, 44.1 kHz or higher) and one annotation file (MIDI/JSON) per instrument.
• Clearly indicate the tier (Standard or Enhanced) and capture method (performed, programmed, or hybrid) for each instrument track.
• Ensure all annotations are human-verified and not generated by automatic transcription tools.
• Supply a brief note on your available genres, instrumentation, and production methods, along with relevant work samples.

Requirements

• Experience as a musician, producer, composer, or audio engineer.
• Ability to capture real audio and MIDI together, or access to an archive of suitable material.
• Proficiency with a DAW such as Logic, Ableton, or Pro Tools.
• Comfortable working to a defined delivery format and technical specification.
• Rights to all material supplied, including permission for AI training and commercial use.
• Genres beyond pop, rock, and Western classical are highly valued; recordings with vocals or diverse instrumentation are preferred.
• Strong attention to detail and accuracy in annotation.

About Twine

Twine is a leading freelance marketplace connecting top freelancers, consultants, and contractors with companies needing creative and tech expertise. Trusted by Fortune 500 companies and innovative startups alike, Twine enables companies to scale their teams globally.

Our Mission

Twine's mission is to empower creators and businesses to thrive in an AI-driven, freelance-first world.