A creepy opening sequence takes place in 1923 and involves a seeming demon named Maestro coming out of a piano when a guy plays the Devil Chord. Maestro ends the sequence by playing the theme music to Doctor Who.

Ruby wants to go to see the Beatles record their first album. The Doctor thinks that is brilliant. Ruby realixes they need to change their clothes. There is a musical interlude while they do.

At EMI studios they pretend to be servants pouring tea at various soundbooths but the Beatles and then another star are singing bizarre and terrible songs.

After buying ridiculously priced tea, Ruby and the Doctor talk to John and Paul. They're depressed and don't want to keep singing these horrible songs. John says he just wants to go home but that makes him cry. Ruby gets through to John and he begins to sing. THe Doctor drops a spoon, everyone is frozen, and the Maestro is cackling from a window. Suddenly John says don't waste my time and leaves.

The Doctor has a piano brought up to a rooftop to try to fix this. THere is huge smog across London visible from the rooftop. The Doctor realizes that his preivious incarnation and Susan are under the smog somewhere. He can't visit them because of timelines. He doesn't know if Susan is alive or dead now because of the Time War.

The Doctor tells Ruby to play the piano. She says she's not good. He heard her playing Christmas Eve. She's the only one who can play. He wants to see what will happen.

Ruby plays a beautiful song she wrote for a brokenhearted friend and people open their windows and are smiling and crying. THen the world shakes and discordant chords play. Everyone screams and shuts their window. Maestro comes out of the top of the piano. The Doctor grabs Ruby's hand and runs.

The Doctor tells Ruby he can't fight this. He thinks it's connected to the Toymaker because the world has gone silent and everything is wrong. Ruby says but music must exist in the future because I exist. The Doctor gets in the TARDIS and takes her back to her own time but the world is a wasteland. THey find the Maestro playing the piano. They are  the Toymaker's daughter and wants to take all the world's music for herself. They say that she was summoned by a musical genius'  chord. Another chord could banish them but they doubt the Doctor is a genius enough to do it.

The Doctor and Ruby go into the TARDIS which seems to be destructing. The Doctor wants to go back to 1963 but all the lights go off. The Maestro is composing and the next tune could be deadly.

The Doctor gets back to 1963. He and Ruby go into EMI Studios and Ruby goes into the sound booth but a bunch of notes turn into vines and tie her up when the Doctor plays John Lennon's guitar. The Maestro is hungry for her music but Ruby refuses to sing for her. The Meastro realizes Ruby's birth involved the "Oldest one in the universe" but won't elaborate. She and the Doctor have this music battle and the Doctor wins. Maestro is weakened until the Doctor plays a wrong note. She imprisons the Doctor and Ruby in instruments but John Lennon and Paul McCartney finally figure out their music and that banishes the Maestro.

THe Doctor performs a long song and dance about there always being a twist at the end. He and Ruby dance through ASbbey Road to the TARDIS and the crosswalk plays music.