Castles In The Air by Don McLean is in E at 120 beats per minute and runs 4:04 across 47 bars. It uses 8 chords — F#m, B7, E, Emaj7, E6, A, F#m7, Amaj7. 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? Castles In The Air guitar melody tab.