Data

Lakh Pianoroll Dataset

We use the cleansed version of Lakh Pianoroll Dataset (LPD). LPD contains 174,154 unique multitrack pianorolls derived from the MIDI files in the Lakh MIDI Dataset (LMD), while the cleansed version contains 21,425 pianorolls that are in 4/4 time and have been matched to distinct entries in Million Song Dataset (MSD).

Training Data

• Use symbolic timing, which discards tempo information (see here for more details)
• Discard velocity information (using binary-valued pianorolls)
• 84 possibilities for note pitch (from C1 to B7)
• Merge tracks into 8 categories: Drums, Piano, Guitar, Bass, Ensemble, Reed, Synth Lead and Synth Pad
• Consider only songs with an alternative tag
• Randomly pick 6 phrases of 4-bar long from each song

Hence, the size of the target output tensor is 4 (bar) × 96 (time step) × 84 (pitch) × 8 (track).

• lastfm_alternative_8b_phrase.npy (3.38 GB) contains 13,746 four-bar phrases from 2,291 songs with alternative tags. The shape is (2291, 6, 4, 96, 84, 8).

The following are six sample pianoroll seen in our training data, where each block represents a bar. The tracks are (from top to bottom): Drums, Piano, Guitar, Bass, Ensemble, Reed, Synth Lead and Synth Pad