Pink Floyd was a musical group known to the Doctor and some of his companions.
The Sixth Doctor liked Pink Floyd, especially the album The Piper at the Gates of Dawn. (PROSE: Business Unusual)
Unlike the Doctor, Sam Jones didn't like Pink Floyd. (PROSE: The Scarlet Empress) Chris Cwej was at least passably au fait with their work, since he knew about Battersea Power Station from listening to Pink Floyd's Animals as a student. (PROSE: Anteus) Ace was reminded of the Pink Floyd lyric, "There's someone in my head, but it's not me", when she heard Azathoth's voice. (PROSE: All-Consuming Fire) And Fitz Kreiner once tried to play "Interstellar Overdrive" by Pink Floyd on his electric guitar, but Anji Kapoor was so unimpressed that she thought he was attempting the Steptoe and Son theme song. (PROSE: The Slow Empire)
Behind the scenes
In the television story The Caretaker, the Twelfth Doctor whistled Pink Floyd's "Another Brick in the Wall" at Coal Hill School. Caretaker does not identify "Wall" as a work by Pink Floyd, but contextually it is exceedingly clear that he is in fact whistling that tune.