Embodiments of the invention are related to a computer-implemented method that includes receiving musical data, identifying a succession of accentuated events in the musical data, determining a pattern in the succession of accentuated events, comparing the pattern to a plurality of reference patterns, and determining a match for the pattern using the plurality of reference patterns. The method further includes selecting one of the matching reference patterns, and generating a rhythmic musical accompaniment for the musical data based on the selected matching reference pattern. In some cases, the musical data is MIDI data or analog audio data. Analog audio data analysis includes detecting transients in the analog audio data by identifying the succession of accentuated event in the musical data. This may include identifying a plurality of events in the musical data, and determining whether each of the plurality of events is an accent.