2025:Symbolic Music Generation

Description

This year, the selected task is piano music continuation. Given a 4-measure piano prompt, the goal is to generate a 12-measure continuation that is musically coherent with the prompt, resulting in a complete 16-measure piece. All music is assumed to be in 4/4 meter, quantized to sixteenth-note resolution, and may belong to any existing piano style, including classical, pop, jazz, and others. Further details on the data structure are provided in the Data Format section.

Data Format

The input prompt consists of 4 bars of piano music, with an additional mandatory pickup measure (left blank if not used). The data is prepared in JSON format containing a property: prompt:

• prompt: a list of notes. Each note contains properties of start, pitch, and duration.

The output generation should also follow the JSON format containing one property output:

• output: a list of notes. Each note contains properties of start, pitch, and duration.

Detailed explanation of start and duration attributes.

1. The data is assumed to be in 4/4 meter, quantized to a sixteenth-note resolution. For both prompt and output, onsets and durations are counted in sixteenth notes.
2. Both onsets and durations are integers ranging from 0 to 17 * 16 - 1 = 271. Notes that end later than the sixteenth measure (i.e., 17 * 16 = 272th time step) will be truncated to the end of the ninth measure.
3. The accompaniment of the pick-up measure should be blank.

Detailed explanation of the pitch attribute.

1. The pitch property of a note should be integers ranging from 0 to 127, corresponding to the MIDI pitch numbers.

Data Example

Below is an example of the input lead sheet in the format given above. The lead sheet is the melody of the first phrase of Hey Jude by The Beatles.

{
  "prompt": [
    {"start": 12, "pitch": 72, "duration": 4},
    {"start": 16, "pitch": 69, "duration": 8},
    ...
  ],
}

This is an example of the generated continuation. Note that the generation starts from the fifth measure (time step 80).

{
  "acc": [
    {"start": 80, "pitch": 41, "duration": 12},
    {"start": 80, "pitch": 65, "duration": 5},
    ...
  ]
}

Evaluation and Competition Format

We will evaluate the submitted algorithms through an online subjective double-blind test. The evaluation format differs from conventional tasks in the following aspects:

• We use a "potluck" test set. Before submitting the algorithm, each team is required to submit two prompts. The organizer team will supplement the prompts if necessary.
• There will be no live ranking because the subjective test will be done after the algorithm submission deadline.
• To better handle randomness in the generation algorithm, we allow cherry-picking from a fixed number of generated samples.
• We hope to compute some objective measurements as well, but these will only be reported as a reference.

Subjective Evaluation Format

• After each team submits the algorithm, the organizer team will use the algorithm to generate 16 continuations for each test sample. The generated results will be returned to each team for cherry-picking.
• Only a subset of the test set will be used for subjective evaluation.
• In the subjective evaluation, we will first ask the subjects to listen to the prompt and then listen to the generated samples in random order. The order of the samples will be randomized.
• The subject will be asked to rate each arrangement based on the following criteria:

• Coherency (5-point scale)
• Creativity (5-point scale)
• Structuredness (5-point scale)
• Overall musicality (5-point scale)

Important Dates (Tentative)

• Aug 7, 2025: Submit two lead sheets as a part of the test set.
• Aug 15, 2025: Submit the main algorithm.
• Aug 20, 2025: Return the generated samples. The cherry-picking phase begins.
• Aug 24, 2025: Submit the cherry-picked sample ids.
• Aug 30 - Sep 5, 2024: Online subjective evaluation.
• Sep 6, 2024: Announce the final result.

Submission

As a generative task with subjective evaluation, the submission process differs greatly from other MIREX tasks. There are four important stages:

1. Test set submission
2. Algorithm submission
3. Cherry-picked sample IDs submission
4. Evaluation form submission

Please check the Important Dates section for the detailed schedule. Failure to participate in any of the stages will result in disqualification.

Algorithm Submission

To be announced later.

Baselines

To be announced later.

Contacts

If you any questions or suggestions about the task, please contact:

• Ziyu Wang: ziyu.wang<at>nyu.edu
• Jingwei Zhao: jzhao<at>u.nus.edu