The museum is only two stories. The permanent collection is all upstairs. To the left are the medieval church-type pieces with a couple of modern depictions of Jesus among them. The next room houses lots of Alpine art, including quite a few pieces by Albert Anker. The central rooms hold a lot of early 20th-century art, including ones by Ferdinand Hodler (among them his famous William Tell piece) and Cuno Amiet, and there are a few Degas, Matisse, and Alberto Giacometti artworks. The last couple of rooms house more modern art from the mid-20th century. Downstairs you find the temporary collections. For more information, you can check out the museum website at www.kunstmuseum-so.ch, but it's entirely in German.
From journal The Afternoon in Solothurn