I just listened to your music "Sky Land" again.
I like how it is in tune (as far Atari 2600 can get), with no sour, or really off key notes.
If you like the buzzy notes, just stop reading.. It is certainly a style of which you can be proud.
I just think there are more regular notes in between so that you could use pure and not buzzy tones.
When I first do a tune, and the Visual batari Basic keyboard has say 2 missing values between F sharp and A and you need the missing G or G sharp, try one or both of the "missing" values. Sometimes it's a perfect fit.
They are no missing values, the frequency goes from 0/1 to 31 for all channels. They are not shown on the keyboard view because they were determined to be so far off the keyboard key that it is skipped.
If you can play the intended note on a keyboard or phone app, go to the Advanced tab and see if there is a pure tone of channel 4 or 12 that matches. If it's unpleasant or way off then of course go to the buzzy tone.
I can do this whole complicated run in only Channel 4 and 12, so I think most tones are there and acceptable.
01 songEndingFinal.bas.bin 4KB