I only watch 'Glee' for one reason... I love music! The fact is they could throw out all the story lines and just sing and I would like the show much more. But as the story lines are geared to introducing the varied musical styles/songs, I endure.
There have been several episodes over the past two seasons that have really stood out, musically, for me. Most notably, "Home" from season one with Kristin Chenoweth ("Pushing Daisies".. and a superb singing voice) and Matthew Morrison ("Will Shuster") performing a mash-up duet of Burt Bacharach's "One Less Bell to Answer" and Luther Vandross' styled cover of "A House is Not a Home". Brilliant performance!
The more I watch the show, the more impressed I am with Lea Michele's ("Rachael") voice. Watching her sing last season I kept comparing her to a young Barbra Streisand and in a few performances she blew me away with her Streisand'esquire singing style and range.
In this episode she performs a wonderful duet with Chris Colfer ("Kurt") of "Happy Days Are Here Again" and pays homage to Streisand in voice and in dress. A Great Performance!
The duets by "Kurt" & "Rachael" and "Mercedes" & "Santana" duet of Ike & Tina Turner's classic "River Deep - Mountain High" are the two superb musical standouts of this episode.