Friends (Various Artists) (1970):  This A&M Records sampler illustrates the reach of this legendary independent record label, with even the more or less familiar bands represented by relatively obscure tracks.  I have no idea how well this album sold (or whether it was even offered for sale at all, but was instead just played on record-store loudspeakers in hopes of drumming up album sales), but I didn’t know a single one of these songs when I came across the record.  Side 1 of Friends opens with a Fairport Convention song and closes with one by the short-lived offshoot band Fotheringay that Sandy Denny formed after she exited that band.  I have a copy of the Quincy Jones album Gula Matari (1970) whence came this version of the Simon and Garfunkel classic “Bridge Over Troubled Water”, and it is a delight from end to end.  Most though not all of the other songs are by hard rock bands.