Mann joined in at Spector's A Little Help From My Friends cabaret show at 54 Below.
The new musical is directed and choreographed by Susan Stroman.
Tunick was honored at the annual gala of Arlington's Signature Theatre.
The world premiere production stars Emily Skinner, Cameron Adams, Jason Graae, and Lynne Halliday.
Tony winner Levi Kreis leads the cast of the Leiber and Stoller revue.
Composer Alan Menken joins the performers as they create a new cast album.
No studio session has ever looked more fun.
Martha Clarke's production of the Brecht and Weill musical currently runs at the Atlantic Theater Company.
Tom Kitt and Brian Yorkey's new musical has been preserved by Masterworks Broadway.
The event took place at the Pershing Square Signature Center.