You can sell affiliate stuff if you did not use the stuff but a high, high, high, really high level of clarity is required to do this. Most bloggers lack this clarity. I recall Tony Robbins selling/being an affiliate for a $25K coaching class. Never took it. Never sat in it. But the guy made millions. He had full clarity in selling without seeing. So he rocked out the selling.
The music industry might not be as strong as it was in the 80s, but there are still plenty of ways to make money online as a musician. Sites like SoundBetter let you sell your services as a songwriter, producer, or session musician to thousands of customers a month. While Musicbed, Music Vine, Marmoset, and SongFreedom are perfect for licensing your music to TV shows, movies, and web series.
Know when to wait. Some affiliate programs require a certain level of traffic, subscribers, etc. If that’s the case, I say it’s better to wait to apply for that program instead of applying and hoping for the best. You risk being labelled the person who can’t follow guidelines and you might also risk not be allowed into the program when you do meet the qualifications.