Julie's plans are dashed by a burst pipe. Idina Menzel gives the Greenies a pep talk, and inspires an alternative.

Chris Colfer teaches the Greenies about the importance of words as they tackle the script for their mashup musical.

When Josh Groban visits for Julie's birthday, he teaches the Greenies to sing from the heart, in perfect harmony.

When Peri is disappointed about playing an ogre, Alec Baldwin reminds the Greenies that acting is about pretending.

Married dancers Tiler Peck and Robert Fairchild teach the Greenies some ballet basics.

Sara Bareilles teaches the Greenies to create their own melodies, but combining lyrics and music takes teamwork.