If you haven’t yet discovered the “100 Albums for $5” monthly feature at Amazon MP3, you really should check it out.

The offerings range from the mainstream to the more esoteric, from new releases (Ludacris, David Guetta) to old favorites (Coldplay’s Parachutes and Camper Van Beethoven’s Key Lime Pie). I usually find at least one or two albums worth adding to my digital collection, and for those who are far less obsessive, you’ll surely find several you don’t already have on CD (best ofs from Sinead O’Connor and J. Geils Band) or missed the first time around (like Radiohead’s Pablo Honey or The Shins’ Oh, Inverted World).

One of the hidden gems this month is a covers collection, Guilt By Association, which features indie artists taking on mainstream tunes. Issued by Engine Room Recordings in 2007, the set includes appearances by Petra Hayden, Devendra Banhart, The Concretes, Bonnie “Prince” Billy, and Superchunk, covering songs from the likes of Journey, Oasis, Take That, Mariah Carey, and Destiny’s Child. One listen to Hayden’s version of “Don’t Stop Believing,” and you’ll think those effervescent Glee kids should do some time in detention for stealing her notes.

Not all of the 15 tracks on Guilt By Association are up to snuff, but it’s still worth the fiver thanks to highlights like Luna’s reworking of Paula Abdul’s “Straight Up.” The 1988 #1 hit enjoyed some major exposure on this season’s American Idol via an acoustic take from finalist Andrew Garcia (6.6 million YouTube views and counting), but the Dean Wareham-led dream pop band (sadly now defunct) adds a nice desolate twang that brings out the longing in the song’s lyrical demand. It even works when Wareham opts for talking the lyrics versus singing.

Purchase Guilt By Association, including “Straight Up” by Luna, for $5 through April 30 via Amazon MP3.