I was just listening to Please Come to Boston by Dave Loggins. It reminded me that he's Kenny Loggins' cousin. Then I started going through the other musical acts that are related, but not part of the same group.

John (Cougar) Mellencamp -> Cousins with Mick Jagger

Whitney Houston -> I forget her relation, but I think there are connections with Aretha Franklin and Dionne Warwick.

There are many, many more.

Whitney's mom is singer Cissy Houston and her aunt is Dionne Warwick.

Aaliyah's aunt was Gladys Knight

Jessica Simpson, sister to Ashlee Simpson

John Mellencamp is Mick Jagger's cousin??? How'd I miss that one?

Norah Jones' father is Ravi Shankar.

It doesn't exactly meet your criteria, but Richard Patrick of the band Filter is the brother of Robert Patrick, the T-1000 of TERMINATOR 2 who also played on the last couple of seasons of THE X-FILES.

One of the guys in Rooney is brothers with a guy in Phantom Planet.

Both bands are beloved by the cast & crew of The OC.

Jim Seals of The Champs and Seals & Crofts is the older brother of Dan Seals, of England Dan & John Ford Coley.

Jools & Chris Holland have both played keyboards for Squeeze, but not at the same time.

Andy Gibb was not in the Bee Gees.

Mike "McGear" McCartney was a member of Scaffold, a musical comedy group. Sean Lennon was a member of Cibo Matto. I don't know that you could call him a member, but Zak Starkey's been drumming for the Who for ages.

Check out Mike McGear's 1974 album "McGear". It's a Wings album (Band On The Run vintage) with Mike McCartney lead vocals.

The guy can take pretty good photies too - "Mike Mac's White'n'blacks".

I have all but one of the tracks from "McGear" on the "Songs The Beatles Gave Away - Volume 4" (The lead track from the album, "Sea Breezes", is the only one on the album not written or co-written by Paul). Vol. 4 is actually something of a Mike McGear-fest as it also has the track "Sweet Baby" (the B-side to Mike's single, "Leave It") and the songs "Dance The Do" and "Bored As Butterscotch" by Mike, and "Ten Years After On Strawberry Jam" by Scaffold.

Ronnie Van Zant of Lynard Skynard was brother to Donnie Van Zant of .38 Special.

...and of course, after Ronnie's death, his brother Johnnie took over as lead singer of Lynard Skynard, so you have Ronnie, Johnnie and Donnie!

Seems to me that one of Stevie Ray Vaughan's brothers was also in the Fabulous Thunderbirds, but I don't remember his name!

Jimmy Vaughan!

The Vaughan Brothers released an album called "Family Style" together shortly after Stevie Ray's death, featuring the creepily topical minor hit "Tick Tock."

Love that one, "Telephone Song" and "Mama Said."

Steve Gaines and his sister Cassie were also in Lynyrd Skynyrd. They were also killed in the same plane crash with Ronnie Van Zant.

I (music.download.com/harrisondemchick) am related to my cousin Rick Friedrich (http://www.rickfriedrich.com).

Does that count?

-Comp