THE SCREENING ROOM: Idina Menzel, Anthony Rapp and Tamika Lawrence Lead Cast of If/Then in "Seasons of Love" Post-Show Sing-Along (Video)

Tony Award winner Idina Menzel and Anthony Rapp — original cast members of the Tony and Pulitzer Prize-winning Rent — and Tamika Lawrence, the "Seasons of Love" soloist in the 2011 Off-Broadway revival of that Jonathan Larson musical, led the cast of Broadway's If/Then in a post-show sing-along of "Seasons of Love."

Idina Menzel
Idina Menzel (Photo by Joseph Marzullo/WENN)

The impromptu performance, captured on video by If/Then conductor Carmel Dean, followed the April 12 evening show of If/Then, when the cast was accepting donations for Broadway Cares/Equity Fights AIDS.

The If/Then cast (unexpectedly) offered the chance for an audience member to join the company onstage and be serenaded by Menzel, Rapp, Lawrence and others from the new Tom Kitt- Brian Yorkey musical. Two audience members, who bid $4,000 each, agreed to share the prize, and $8,000 in total was raised from the "Seasons of Love" auction.

Click here to read about director Michael Greif and cast members Menzel and Rapp— a trio of Rent originals — who reunite 18 years later in Broadway’s If/Then.

If/Then, the new musical about a woman starting over in New York City, opened March 30 at the Richard Rodgers Theatre.

Watch "Seasons of Love" below: