Low frequency multiplier... Suggestions/info needed.

[HankMcSpank]

Wow Henrik...you really went the extra mile there - top man!

Without wanting to hijack the thread, if you weren't constrained by the relatively low featured pic .....do you (or anyone else with experience) think it would be possible to detect pitch quickly - then output a multiple of it (say between 20.xxx% & 100%), so for example...

if incoming frequency is 110Hz ('A' note)- then output 138.591 Hertz ('C#' note)

Rather than using a LUT, I reckon I really need to multpily the incoming frequency ....becuase for sure there'll be occasions when the arriving frequencies are not quite as expected (instrument not in tune).

Would such granularity be achievable? (eg detect the incoming frequency to XXX.yyy resolution then multiply by say 25.xxx%!)