Greetings; I'm told that matlab can do this, but this is a one time deal on a home made instrument. I've not that sort of money to spend. Do we have anything for linux that can take a microphone input to an audio card, do an FFT on what it picks up that is accurate to small parts of a hertz at frequencies in the 1st two octaves of a keyboard? Thanks all. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> * knghtbrd does the ET thing <knghtbrd> anybody got a speak-n-spell?