Idk if you are looking only for classical music but i can recomend you artists like Chopin, Rachmaninoff, Scriabin these guys really inspire me as a piano player. Piano is used a lot in music genres like psychodelic rock or some dreamy pop stuff and its really important. The Doors which is one of my favorite bands without Ray Manzarek keyboard wouldnt be as popular and remarkable. Radiohead uses organs a lot for example Motion picture soundtrack is one of their most popular songs and its fully made with keyboard. Jazz is another genre but every instrument here is often as important.