In this paper we report on preliminary experiments in the
study of microtiming features in Samba music.
Focusing on polyphonic audio music with almost constant tempo, 
we propose an algorithm to discover from data in a bottom-up manner
systematic timing deviations at the 16th-note level
in quarter-note-long temporal patterns.

Our analysis of the data highlights a systematic 
shift of third and fourth 16th-note beats, slightly ahead of
their corresponding quantized positions.