The event will be presented Aug. 12 at 8 PM at The Highline Ballroom.

The lineup also includes Emma Hunton, Corey Mach, Coleen Sexton and Preston Sadlier, who will join previously announced Nick Cartell, Robin De Jesus, Rebecca Faulkenberry, Jason Gotay, Michael McElroy, Taylor Noble, Lauren Pritchard, Kacie Sheik and NYC a cappella group BLACKOUT for the 90-minute concert.

Musical accompaniment will be provided by Bobbie L. Crow III on cello, Rick Ippolito on bass, Simon Kafka on guitar and Cody Rahn on percussion.

Pfeil's music has been featured at Joe's Pub, New World Stages, 54 Below, (le) Poisson Rouge, as well as The Bitter End, where he is a member of the Singer/Songwriter Sessions. His debut EP, "Crossing Connecticut," will be released in September.

Sarnak wrote the book, music and lyrics for The Quad, developed and performed at Harvard's Loeb Experimental Theatre. Sarnak has four full-length musicals in development, including Mixtape, featured in Silent Street Productions' 2012 season, PainLess (with book by Michael Kimmel) and A Lasting Impression.

Overcash's musical Boys Vs. Girls was recently optioned, and his other shows — Joe, To You With Love and Rhapsody — are all under development. His music has been performed at Joe's Pub, Birdland, 54 Below and (le) Poisson Rouge.

The Highline Ballroom is located at 431 W. 16th St. Tickets are $15 in advance and $20 at the door. For more information and tickets, visit highlineballroom.com.