Joni Mitchell, yes of course, but it would have to be "Blue", got me through my teenage angst years, more or less in one piece.
Blue Nile, but "I walk across the rooftops"
Puccini La Boheme, only if it's the Beecham Version with Jossi Bjorling and Vittoria De Los Angeles.
When she enters in the first Act, it's really like an angel has entered the room.
If I could have just one more it would be Martin Simpson's "Solid Air"