A surprising compilation album from the duo Chemistry, this one collects a series of pieces done in combination with other artists, ranging from related pop acts to American instrumental virtuosos.

There's a distinct groove to the proceedings here, with heavier synth sounds taking place throughout the music, a slight departure from the more ballad-heavy repertoire that Chemistry are perhaps known for.

Despite being a collaborative album, though, the focus is very strongly on Chemistry here.

A collaboration with Jake Shimabukuro verges on sacrilege as there are but a handful of bars using the ukulele master.

An Auto-Tunes-heavy track with Gekidan Hitori fuses the vocals together enough that there isn't a lot of distinguishable information left to separate the singers.

The hit "Rainbow" almost entirely uses the main voices of Chemistry rather than their collaborators.

The criticism that Dochin Yoshikuni and Kawabata Kaname focus on themselves too much in a collaborative album notwithstanding, the Chemistry duo does put together a nice sound.

The compositions are in many ways less adventurous on this album than on some of their main studio albums, but their attention to emotion in balladry is still present.

It's simple, male vocal pop that stays on the side of R&B rather than full-fledged boy band material -- straightforward and to the point, once the anonymous dance tracks get out of the way.