20 Good Reasons by Thirsty Merc is in Gb at 94 beats per minute and runs 3:11 across 59 bars. It uses 21 chords — C, Db, Cmaj7, Dbmaj7, F, Gb, G, Ab, 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? 20 Good Reasons guitar melody tab.