It's strange that a band with a song as immediate as "All Right Now" is a bit of an acquired taste, but it's the truth. Free was a powerful, majestic hard rock band at their peak, but they were also a little obtuse; a lot of their power came from their playing, and their songwriting was epic, but often elliptical. As such, they're for hard rock connoisseurs – a band who gained a spirited, dedicated following largely because they took devotion to unlock their treasures, especially in the years following their breakup. For those fans, the five-disc Songs of Yesterday is a godsend. This is not a box for listeners with less than a consuming interest in the band (even if you think you want total immersion in Free, this will not be as effective as purchasing each of their albums) since this contains a wealth of unreleased material. Very few of the tracks are actual album tracks, most are alternate mixes or alternate versions, plus there are a lot of live tracks in the mix, as well.