I'll jump in here. Yes, I did a lot of commercials. Back in the early 90's, when I was living in California (Merced to be exact) I did a lot of session work for KRP Studios. KRP was located in Atwater CA (where Castle AFB is located). We developed a rather large library of "jingles". Bob Pogue was the owner and engineer at KRP. It was in the analog days. There were several musicians involved in this work. We had a drummer, bass player, keyboard player, and a pedal-steel guitar player (for country stuff). I was the resident guitar player. Back in the day, radio and TV commercials were 15 seconds, 30 seconds, 45 seconds, or 60 seconds. We would brainstorm a musical idea, and then take a run at it. We made hundreds of jingles for the various time formats. Radio and TV stations bought the music jingles, and then did voice-overs.
As musicians, we provided the music, but never had any idea what product the music would be used with. My music has been used to sell everything from appliances to zip-line excursions. The "Fantasy Room get-away" at a local hotel was my personal favorite. There was the cave room, the bordello room, the mirror room, you get the picture. We never made any residuals, but were pretty well paid for the studio time. Some of the jingles ended up on TV, but most were radio. It really helped hone my songwriting chops, and helped support my family so I considered it a win. The other musicians were great players and very spontaneous. It made me put my best foot forward, so to speak.