The Warblers were introduced in the episode 'Never Been Kissed' on this season of Glee. The Dalton Academy glee club is composed of an all-boys ensemble, including show regulars Kurt (Chris Colfer) and Blaine (Darren Criss).
According to TV Guide, the show will release an album that features only music from the Warblers in April. The album will presumably be comprised of songs performed during the second season of the Fox series, including Katy Perry's 'Teenage Dream', Train's 'Hey, Soul Sister', Destiny's Child's 'Bills, Bills, Bills', Robin Thicke's 'When I Get You Alone' and Wings' 'Silly Love Songs'.
Upcoming songs that will be performed in future episodes include Neon Trees' 'Animal' and Maroon 5's 'Misery'. These songs are likely to be featured on the album as well.
Glee airs Tuesdays at 8pm on Fox.