Apart Together (Kissing the Outkasts)
I've been mulling this whole "solo albums by group members" thing.

Normally when members of a group start issuing solo albums, they're independent efforts that don't really have anything to do with what the main band is doing. Examples include the solo efforts of the Beatles prior to Abbey Road, Alan Wilder's Recoil project which started while he was still part of Depeche Mode, and Phil Collins' solo work while he was still a member of Genesis. Even the recent Martin Gore/Dave Gahan solo efforts are independent of Depeche Mode (no matter what the Depeche Mode website might have implied earlier in the year).

I've been racking my brain and can only think of two instances in which a music group coordinated simultaneous releases of solo albums by group members.

In 1978, KISS was riding a huge wave of popularity when they released four solo albums. The Gene Simmons, Ace Frehley, Peter Criss, and Paul Stanley albums were released with similar album covers, and were all released on September 18, 1978. Ace Frehley clearly won the battle of the soloists (to this day the only song that I have heard from any of the four albums is Frehley's hit "New York Groove"), probably because (as noted here and elsewhere) he had only sung on two songs prior to his solo album release. In addition, "[t]here are a lot of weird sound effects that can be heard on the album which shows that Ace was willing to make the most of his solo effort by experimenting with different sounds." While the original lineup went on to record another album (Dynasty), Peter Criss only appeared on part of the album, and didn't appear on Unmasked at all. Peter Criss left KISS in 1980, followed by Ace in 1982. (Both would return several years later.)

The second example of coordinated solo releases is OutKast's "Speakerboxxx/The Love Below" project, and although it's too early to say what effect this will have on OutKast in general, there are a few things that can be noted. For one, while each of the members controlled their own albums, each artist lent production assistance to the other's set. In addition, this is not a case in which one or more of the band members needs to resort to a solo album to get his songs played (George Harrison, Andrew Ridgeley, Dave Gahan) - both Andre and Big Boi have contributed to OutKast's output. However, the double album does allow each individual to explore things that would be hard to explore otherwise; for example, Andre noted: "My album isn't really a hip-hop album but rather an album done by a hip-hop person....It's more melodic, more singing, and that's why I wanted to do it as a side project." Big Boi stated: "The best part of it was the challenge of writing a whole song without having Dre come grab the baton when it was time to pass it off."

Whether group members release solo albums in coordination or in frustration, it's interesting to hear what happens when (if) the group members get back together again. Many of us are watching Depeche Mode to see who ends up writing the songs on their next album...