Once I Loved by Antonio Carlos Jobim is in Gm at 160 beats per minute and runs 1:12 across 22 bars. It uses 25 chords — G7, Gm7, A7#5, Dm, D7, C9, Fmaj7, F#dim7, and a few more. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? Once I Loved guitar melody tab.