Amy and Rory were walking through the TARDIS, trying to find the Doctor. They were opening various doors and going down random corridors, bored of waiting around in the TARDIS.
"Where could he be?" asked Amy exasperatedly, closing what felt like the millionth door.
"The TARDIS is almost endless, so he could be anywhere," replied Rory, opening and closing another door.
"That's not very helpful, Rorrryyy," Amy drawled.
"Sorry, it's just-" Rory got cut off from someone singing.
"Is this someone screaming or singing?" he asked, as he and Amy dashed off in the direction they heard it come from.
"I don't know, but I know that the someone, is the Doctor," said Amy, turning right.
They walked in on the Doctor, Amy's mouth dropped open.
The Doctor was wearing a purple bow tie, instead of his normal red or blue one, and he was wearing a guitar which was hanging from his form, and holding a microphone in front of a recording device.
"SO SAY GERONIMO! SAY GERONIMO! SAY GERONIMO! SAY GERONIMO! SAY GERONIMO! SAY GERONIMO! Can you feel my looovee," they heard him singing at that top of his lungs.
"DOCTOR!" Amy had to yell to be heard of the music and his singing.
"Ponds?" his head snapped toward them.
"Explain," said Amy, crossing her arms.
The Doctor looked slightly embarrassed, "You see, River complained that I don't confess my love her as much as she would like. Basically, she bet me that I couldn't write, and sing a song a love song dedicated to her. Of course I did it, she's River, so I wrote it and then-" Amy cut him off.
"So you wrote a song with the word 'Geronimo' in it over and over again?" asked Amy.
"Well, what else was I supposed to put in the song? There is another line as you heard, but yes, I'm calling the song 'Geronimo!'" the Doctor replied, "And I'm going to publish it for the world to see, in the official lyric video, I will put, 'For the River that never ends' she is bound to see it, and she will know how much I love her."
"Well, um, that is actually… quite creative," said Rory, confused.
"Yes, but now, you Ponds, have interrupted my recording, so now I have to do it again, and then make a clever lyric video and put the dedication in," said the Doctor, flipping back to the start of his notes.
"So… we're not going to see a planet or history, or any fun stuff today?" asked Amy.
"Not until, I finish this for River, now go along Ponds," he said, about to press the record button.
"Allrigghtt, come on Rory, there must be something in this endless ship," Amy said, annoyed, and led her and Rory out of the room.
"SO SAY GERONIMO! SAY GERONIMO!" they could hear the Doctor singing at the top of his lungs.
"DOCTOR SHUT UP! YOU SOUND LIKE A DYING CAT!" Amy yelled, "IF YOU WANT TO RECORD IT, DO IT QUIETLY SO WE DON'T HAVE TO HEAR!"
The Doctor didn't say anything, but they didn't hear a peep out of him until he was done.