Magnum Opus: 20 Dance Masterpieces is a double-disc set that includes some of the best dance singles of the '70s and '80s, spanning disco, funk, soul, and house. There were so many great singles that came from this era that it would be impossible to come up with something definitive in the space of two discs. The greatest strength of this compilation is that it doesn't include any of the obvious staples that have already populated dozens of other packages. Even the most familiar songs here -- Shannon's "Let the Music Play," Diana Ross' "Love Hangover," Donna Summer's "I Feel Love" (Patrick Cowley's 16-minute 1981 version!) -- are hardly as played out as, say, the Village People's "YMCA" or Wild Cherry's "Play That Funky Music." Instead, there are Indeep ("Last Night a DJ Saved My Life"), Roy Ayers ("Running Away"), Rene & Angela ("I'll Be Good"), Bohannon ("Let's Start the Dance"), Yarbrough & Peoples ("Don't Stop the Music"), Central Line ("Nature Boy"), and Cameo ("Single Life"). In other words, one is more likely to hear these songs during an urban radio station's after-school flashback show than a trailer for a new movie. The other key advantage this compilation has over most of its competitors is the fact that most of the songs are presented in their full or 12" mix versions; most compilations attempt to cram as many songs as possible onto one disc, so they favor radio edits that usually pale in comparison to their superior counterparts. So, this is hardly your everyday retro-dance compilation; it was obviously put together with loving care.