Rock stars don’t get more unassuming than Maurice Gibb, by far the quietest Bee Gee. Of the three Brothers Gibb, Maurice made the most instrumental contributions (on bass and keyboards) but took few lead vocals, leaving that to brothers Barry and Robin. He also kept the lowest profile on stage and in videos. And in the photos of the trio from the height of their disco years, Maurice was the one brother who had the good sense to button his shirt instead of exposing his chest hair.

But to associate the Bee Gees with disco is like associating Paul McCartney with "Silly Love Songs": they did that, and a lot more. The Brothers Gibb were a classic-model songwriting team, trying their hands at numerous styles over the years. They were steered toward disco only when their manager, Robert Stigwood, needed a few songs for a film he was producing. The result was Saturday Night Fever (1978), arguably the biggest pop-culture sensation of its time. Stigwood’s next bright idea — a film based on Sgt. Pepper’s Lonely Hearts Club Band, starring the Bee Gees and Peter Frampton — did considerably less well, and it’s a tribute to the Bee Gees that their career, unlike Frampton’s, was able to recover.

Their disco-era work had its pleasures, guilty and otherwise — no apology is needed for a song as beautifully crafted as "Nights on Broadway." But there’s no doubt that the Bee Gees would have more critical cachet if they’d stopped recording in 1970, because none of their records before that point was less than wonderful. I’d refer cynics to an import double CD, Brilliant from Birth, which brings together the early singles and demos they recorded in Australia. Over 60-odd tracks, they try everything from spirited Beatles sound-alikes to imitation folk songs and operatic pop (classic title: "I Was a Lover, a Leader of Men"). And it was all the work of young teenagers whose voices, on the earlier tracks, hadn’t even changed yet.

Moving back to their native UK in the mid ’60s, the Bee Gees produced some of the oddest and most beautiful hits of the British Invasion. Most were informed by a profound sense of melancholy. Of their first four international hits, three were about dead people ("I Started a Joke," "New York Mining Disaster 1941," and "I’ve Gotta Get a Message to You"). The fourth was "Massachusetts," easily the best song about this area to be written by people who hadn’t as yet been here.

Unlike his two brothers, Maurice never made a solo album. But he was behind a record that became a small legend among Beatles collectors: "Have You Heard the Word," issued on a small label in 1968 and credited to the Fut. Wrapping all the trademark sounds of the Beatles’ psychedelic era into three minutes, it’s such a good homage/parody that many bootleggers mistook it for the real thing; it was eventually revealed that Maurice put it together himself, after a heavy night of clubbing with the Fab Four. He deserves a bit of immortality for that one alone.