There aren't any widely used ones on Steam, which is a big problem because you need to go with the masses when it comes to music production in terms of what program you use, or else you run the risk of there being no tutorials or plugins to make music with. You'll want to look into things like Cubase, Fruity Loops Studio, Ableton Live and other stuff like that. Since you mentioned getting them on Steam I presume you want to get them legally, so you'll need to keep in mind that they're ridiculously priced because they're professional software, and on top of what you pay you also need to buy plugins to refine the sounds you make. Honestly just fucking pirate them. That's literally how every music producer starts (yes, including all the massively popular people), because its ridiculous to expect someone to pay a few hundred to a few thousand dollars/pounds/euros for programs that complicated right off the bat. Do this. Hell just about anyone can learn how to use the basics of any DAW and its fairly simple to just get started with something like FLStudio