Oh, definitely, playing music can get muscles in the forearms and wrists! What do you play?
On the push-ups, to adjust the intensity or to target different muscle groups you can vary things like:
--Angle of hands
--Distance of hands from body
--Height (either by raising your hips higher off the floor or using handles that elevate you off the floor, like gymnasts use)
--Angle of body (using an incline)
--Number of hands (1 instead of 2)
You can experiment with that and notice how playing with those affects the way it feels. To give one application;
The pushup position stresses the pecs as the elbows move out to the sides, away from the body; it stresses the triceps when the elbows stay in close to the body. So if you want to work your triceps, instead of holding your hands in the regular pushup position, bring your hands in to within less than shoulder-length apart and lower your body to the floor, keeping your arms in against your body. In the "up" position, your arms should angle back towards your waist. As you lower yourself, pull your arms in against your sides. This will increase the tension in the triceps.
For a variation of that, point your fingers out instead of forward to shift the emphasis from your outer to your inner triceps.
That's one example; will send some more stuff on that after I get a chance to write it up. But meanwhile play around with that principle and see what you come up with.