So, while I congratulate you on your resourcefulness and success, I think this advice is very particular to where you live, whether you even like local music, do you understand page layout design, good writing etc.
It's a good story (my daughters thought it was cool that their dad was in the local music scene) but lousy advice.
As for going door to door asking businesses for work? Nope. It sounds perfectly plausible but doesn't pan out so well in reality (I've done it). Wearing my business blazer, a pocket full of business cards and a really great deal on a small business website, I went from business to business all. day. long. I explained who I was, what value I could bring to their company etc but got nothing.
Why? I think because they had no intent to buy, or even an expressed interest or need. I was just one of many people walking in through their door trying to sell them something.
And that's the thing: if you are a local business with a brick and mortar establishment in a reasonably trafficked area, you are going to have as many people visit your store to sell you something as to buy something. Most times they will politely listen to your pitch, take your card, then never speak to you again.
So again, while the advice sounds plausible, it's not actually a way to make quick cash or even build a client base. Even if you want to make money "badly enough".
P.S. Desperation doesn't sell.