We derived the labels for the Lakh Pianoroll Dataset (LPD) from three different sources: the Last.fm Dataset, the Million Song Dataset (MSD) Benchmarks and the Tagtraum genre annotations. Note that these labels are derived based on the mapping between the Lakh MIDI Dataset (LMD) and the MSD, which may contain incorrect pairs (see here).
Please refer to the original sources for the license information.