A lead sheet is a type of music notation which summarizes the content of a song. The usual elements that are reproduced are the melody, chords, tempo, time signature, style and the lyrics, if any. In this paper we propose a system that aims at transcribing both the melody and the associated chords in a beat-synchronous framework. A beat tracker identifies the pulse positions and thus defines a beat grid on which the chord sequence and the melody notes are mapped. The harmonic changes are used to estimate the time signature and the down beats as well as the key of the piece. The different modules perform very well on each of the different tasks, and the lead sheets that were rendered show the potential of the approaches adopted in this paper.