Hi y'all
further down there's a lengthy discussion on tuning, and the mention of buying an expensive peterson strobe tuner as the way to go. I don't think this is really necessary; i bought a peterson VSAM last year but rather use an old Roland TU chromatic tuner most of the time, together with my ears. BUT if you have an old laptop computer with an external or internal microphone laying around, try the Windows AP tuner, see link #3. Cool thing, even has just tuning settings, shareware though, but it works as it is, even without registering ..... - Nout

Here is another tuner built just for accordion tuning. It allows you to sample and tune 3 reeds at once. A free trial is available but does not include all the notes.
Greg

Hi Greg; tried that one too once, but felt the AP is more to my liking, maybe it's even more acurate too. - nout