WATCH: Meryl Streep, Christine Baranski & Tracey Ullman 'Sing' Rob Marshall's Praises

With eye candy like the cast of Looking on hand as presenters, and Meryl Streep stopping by to take part in an Into the Woods medley, there was plenty of swooning and crooning at last Thursday's 30th annual Artios Awards, the Casting Society of America's (CSA) toast to the year's finest achievements in casting.

Held in New York at the 42West Cabaret & Lounge (and simultaneously in Los Angeles at the Beverly Hilton), the event was an exceptionally gay affair: Michael Urie hosted; Looking stars Jonathan Groff, Murray Bartlett, Raul Castillo, and Frankie J. Alvarez turned out to bestow trophies; and multiple honors were handed to the casting team behind Orange Is the New Black.

But the highlight of the evening, and the moment that had everyone whipping out their smartphones, was an unexpected musical performance by Into the Woods stars Christine Baranski, Tracey Ullman, and the one-and-only Meryl Streep, who emerged on stage in a glam jumpsuit to roars of applause.

In their tuneful lead-up to presenting director Rob Marshall with CSA's career-celebrating New York Apple Award, Streep and company performed a live mash-up of multiple Into the Woods numbers, tweaking the lyrics to honor the man who brought them together on set ("Rob took us all to the festival," went one familiar passage).

The cast of Looking was in attendance as presenters.

While accepting his accolade, and playfully acknowledging the tough act he had to follow ("You rehearsed that!" he shouted at the ladies), Marshall was keen to highlight the efforts of the casting directors who filled the room--people whose work, typically, isn't widely understood by the general public. "People don't know what you do," Marshall said, "but this amazing cast [of Into the Woods] would never have happened without you. What I most love about this film is you care about the people who are in it." Marshall also thanked producer John DeLuca, his partner in work and life. "I can do what I do because he does it with me in such a gorgeous and supportive way," Marshall said.

After Marshall and his actresses left the stage, Urie, who had plenty of quips to offer all night ("Those Looking boys really know how to talk into a microphone, you know what I mean?" he said at one point), gave a slight jab to the parallel ceremony happening on the West Coast, where many of the night's recipients were based. Still reeling from the medley, he said, "I mean, you think they had that in L.A.?"

Watch the full video of the musical performance and Marshall's speech below. For a list of all the 2015 Artios Award winners, click here.