Previous answer by bybe reaches right conclusion - stick with the domain name you have. Already established site has considerable advantages and any lift you might get from an exact match domain is overwhelmed by the potential downsides of moving site over.
If you were keen to make use of the new domain name, I would build a small mini-site that is specifically about piano tuning and Toronot + surrounding areas. That is the only way you can make use of the new domain name. Forwarding the name to the existing address will yield exactly zero benefits.
Instead of worrying about the domain name, there are many things you could do to the existing site to improve it's search performance.
Adding keyword rich paths is important suggestion previously mentioned
Also, you do some silly things like the keywords 'piano tuning in toronto' in footer area link to a page with path /rates with all sorts of poorly structured content (from an SEO perspective, at least) when you have an actual page with the path /piano-tuning-toronto
As well on the page /piano-tuning-toronto, you should really think through the SEO logic of the content you've got there. Aside from the path and the page title, the rest of it stinks. E.g., the word 'Toronto' appears only in the title and nowhere else (aside from footer which Google will discount almost entirely). 'piano tuning' doesn't fare much better, but is there at least 2 other times.
Customize the meta descriptions for each page so they are unique and relevant to the content of each individual page
Change paths like /pianosforsaletoronto to use hyphens
Replace the animated gif with text panels that Google can read.
I would also advise to fix all the typos in your sidebar text (and perhaps elsewhere) so your site appears more professional. I don't know that Google will specifically penalize for this sort of thing, but it would not surprise me. Certainly, it looks bad to have such visible text contain so many errors.