Tonight's episode of 'Glee' (April 15) finds the cast feeling "tested" in all sorts of trying situations.

When the guys get tested for STD, Artie's results come back positive. In the wake of the news, he's forced to address the issue with all of his sexual partners. (Yikes!) Additionally, Kurt and Blaine's relationship is strained when Blaine gains the "freshman 15."

Naturally, all of the drama will be interspersed with some amazing covers. Artie rocks out to Robert Palmer's 'Addicted to Love.' Seriously, this number brings the energy! Another song we love, love, love is Mercedes' power ballad, 'I Want to Know What Love Is.' This Foreigner cover might be one of our favorite 'Glee' performances ... ever.

Mercedes also teams up with Artie and Sam to sing Janet Jackson's 'Let's Wait Awhile.' Lastly, Blaine and Kurt bring a show-stopping performance of Pat Benatar's 'Love Is a Battlefield.'

Check it all out on tonight's new episode of 'Glee,' airing at 8PM ET on FOX.

Listen to 'Addicted to Love'

Listen to 'I Want to Know What Love Is'

Listen to 'Let's Wait Awhile'

Listen to 'Love Is a Battlefield'