In the odd pairing department, Lou Reed and Metallica have joined together to record an album of 10 new Reed compositions.

The metal band and pioneering rocker entered Metallica’s studio near San Francisco, according to Rolling Stone, which describes the set as a cross between Reed’s dark “Berlin” and Metallica’s “Master of Puppets.”  That sounds like a really tall order since both are considered classic sets.

The union came about after the two titans played together at the 25th Anniversary Rock and Roll Hall of Fame concerts in October 2009. Metallica backed Reed on two tunes.  That set the wheels in motion.

Initial plans called to cut older Reed material, but shortly before recording started, Reed changed gears and suggested they record a song cycle he wrote for “Lulu,”  a play running in Berlin. Metallica then crafted arrangements for the tunes.

Of course, they think the project is awesome. Reed told Rolling Stone is was “a marriage made in heaven,” whereas Metallica drummer Lars Ulrich said “I don’t think we’ve ever felt this free.”  Ulrich adds the set is "90 percent" done.

Speaking of freedom, it turns out that Metallica is done with Warner Bros. and Reed doesn’t have a current album deal so there’s no word yet on which label will release the collaboration.