"Jailhouse Rock"-Chris Fountain (plays Justin Burton)
"Unbelievable"-Gemma Merna (plays Carmel McQueen) and Andrew Moss (plays Rhys Ashworth). This song also includes Carley Stenson (plays Steph Dean) and Chris Fountain (plays Justin Burton)
T-Rex Medley-Kevin Sacre (played Jake Dean), Loui Batley (plays Sarah Barnes), Summer Strallen (played Summer). This also includes Gerard McCarthey (plays Kris Fisher).
"Amy Josh Forever" by the Baby Diegos- Ashley Slanina-Davies (plays Amy Barnes)
"Play" by the Dirty Diegos - Hollie Jay Bowes (plays Michaela McQueen). If you youtube this song, you'll find the actual video.
Now, those are just ten examples of people that can sing, and not all of the videos are ONE person singing...so really it would probably be more. The following are people that I know or heard can sing, but I couldn't find a video for them.
Sonny Flood (Josh Ashworth)
Garnon Davies (Elliott)