McCabe, a senior at Deering High School in Portland, walks down the hallway toward the music practice room before performing her elaborate "promposal" for her friend, sophomore Elliott Weeks. “Why not go all out once in front of everyone?” McCabe said. “I’m a senior. I can just graduate the embarrassment away.”

Members of the band TBD rehearse their "promposal" version of "Come On Eileen" in a tiny soundproof music room at Deering High School in Portland. From left, McCabe, Caroline Hodson, Helen Bellafiore, Jade Bucha and Spencer Todd.

McCabe quickly writes "Prom?" on a whiteboard in a classroom before her elaborate "promposal" in the front hall of Deering High School.

McCabe walks through a group of students before her elaborate "promposal." She decided to do something flashy to formally invite her friend to accompany her to the prom.

Students look to the stairs waiting for sophomore Elliott Weeks to walk down for his elaborate "promposal," a surprise staged by his friend McCabe and their band, TBD.

Deering High School sophomore Elliott Weeks walks down the stairs as McCabe and their band, TBD, start playing their version of "Come On Eileen," as a musical invitation for Weeks to go to the prom with McCabe.

Weeks is surrounded by other students as he listens to McCabe and their band, TBD, perform.

McCabe and bandmates perform in the front hallway of Deering High School. Her joy is evident.

A crowd flanks Weeks, at left, as his bandmates play the "promposal."

Students cheer as McCabe with the band TBD perform the song "Come On Eileen," replacing the well-known lyrics with clever prom rhymes and substituting the name Elliott for Eileen.

Weeks, center, jokingly pretends that he has to think about saying yes after his friend Katie McCabe's "promposal."

McCabe and Weeks hug after he said yes to her elaborate "promposal" in the front hall of Deering High School.

The band TBD shares a laugh after Katie McCabe's successful musical "promposal." From left, Jade Bucha, Ethan Weeks, McCabe and Spencer Todd. When McCabe and four other seniors formed a band over the winter, they asked Weeks, a sophomore, to be their drummer.