Our chart department has been dealing with this issue all week, and as a result, you'll notice that credits for some of the "High School Musical" tracks have changed.
It's really not a Milli Vanilli situation, though. The Disney folks never claimed that Zac Efron was singing all of the "High School Musical" songs. On the CD, songs are credited to character names, not the names of the real actors. Billboard listed the songs on the chart by using the actors' names. It's also not unusual for actors not to sing their own songs in filmed musicals (Marni Nixon became famous for being the singing voice of Audrey Hepburn, Deborah Kerr, Natalie Wood, Jeanne Crain Marilyn Monroe in various movie musicals).
Andrew Seeley did sing some of the "High School Musical" tracks, and has been properly credited on the Billboard charts. On other tracks, Zac Efron recorded vocals and they were mixed with Seeley's vocals, so both artists are now credited.
By the way, the success of all these "High School Musical" tracks was completely unexpected. Label execs at Walt Disney were planning to promote B5's version of "Get'cha Head in the Game" as the hit single from the TV movie. Ironically, it's one of two original songs on the album that has not charted.
Songs are credited to character's names??? Is that so Disney doesn't have to pay the real people?
I'm sooo disappointed. I don't know if I'll ever be able forgive Zac.
I just hope he hasn't broken Fredrick Quagmire the Third's heart!