does anyone know de notenclub its a show on the dutch television

in the show there are 2 teams, one from belgium, and one from the netherlands (as usual ;))
the pianists are fixed, the other 2 on the team are guests and different every week
each team has to gain points by finding some songs and singing them

the songs they have to find have to contain a certain given word.

so for example they are given the word 'piano', they can then think of the song 'the piano man' by billy joel. the pianist of the team then plays the song, and they have to sing the song to keep their turn.

there are some more parts in the show .. but this is the part which made me and my gf wonder.

sometimes the guests have relatively unknown songs, adn the pianist has to play them ... they always manage!

do the pianists know all these songs ? or is part of the show fake and is a list of songs submitted to the guests (as the words they have to chose from arent that difficult :))

does a professional pianist literally know thousands of popular songs ? (and maybe more :))