The MAPS dataset is one of the most used benchmark dataset for automatic music transcription. We propose here an updated version of the ground truth MIDI files, containing, on top of the original pitch, onset and offsets, additional annotations. The annotations include: Tempo curve Time signature Durations of notes in fraction of a quarter note (some of them are approximate) Key signature (always written as the major relative) Separate left and right hand staff Text annotations from the score (tempo indications, coda...). If you use these annotations in a published research project, please cite: Adrien Ycart and Emmanouil Benetos. “A-MAPS: Augmented MAPS Dataset with Rhythm and Key Annotations” 19th International Society for Music Information Retrieval Conference Late Breaking and Demo Papers, September 2018, Paris, France. More information is available at: http://c4dm.eecs.qmul.ac.uk/ycart/a-maps.html Version 1.1 (2018-09-19): BUG FIXED: in some files, the time signature, key signature and text annotations used to be incorrectly shifted by one quarter note. This is now fixed. Sustain pedal activations are now the same as in the MAPS dataset, they are all in the "Piano left" track.