Thanks for the input regarding the gaps.
I found out about the position by a help wanted sign on their door. The sign said to leave a resume.
I've left resumes with this store more than a few times in the past, including when they have had Help Wanted signs on their door. I've never gotten a callback. This would be my first time leaving a cover letter with the resume, with my intention in the cover letter is to let the store (a music store--the kind that sells CDs and records, not instruments) know that I have an extensive knowledge of music that would be an asset to them, which is not reflected in my resume as I've never worked in the music or retail industries. I also want to let them know I would be excited to work there, as I patron their store all the time. And again, this a music store, not walmart or target. I shop there because I have a passion for music and I love shopping at their store, not because I see shopping there as a "necessary evil", such as with a Walmart or Target or what have you. This is also not reflected in my resume.
Please let me know if you still think its a good idea to dump the cover letter. Any help is appreciated!