Thanks David, I forgot to check the Preferences since I started to use PurrData.

I am using Purr Data Version 2.3.1 (20170828-rev.aaf525e).
I am not able to output any MIDI. I test this with Snoize MIDI Monitor: PD out is available, but nothing is coming through.Like with this simple sound to midi notes patch

sound to midi.pd

It would be nice to list the libraries you used. I see tons of errors: "...could't create".

I get error

svf~ low
... couldn't create

Pd-0.47-1-64bit on mac

Here, I got it.
You can run an audio track and play MIDI synth along with it by tapping a mic(or drum trigger in my case).
It will be used in dance performance where flamenco dancer plays music by clogging the floor.
It needs some tweaking of sensing parameters though
I am pretty happy with my first real PD project. Thanks, David!

tap notes along.pd

OK, first part is working.
Now for the bonk~

sound play ram to midi.pd

BTW I find sometimes easier to send AllNotesOff CC message 120 or 123 than noteon with vel 0. Specially when you are triggering notes in rapid order(the way I like to with my interactive installations). Even if I use noteOff I put this AllNotesOff in 1sec interval in case some notes get hung.

Thanks. I am learning by doing.
However this method tends to send vel 0 most of the times - noteOFF(test works OK though). I think it receives notes from fiddle~ with velocity 0-127 and at the time of bang it may be at 0 more often than not.
I tried [makenote 127 500] as well hoping that the note number would change only and will be sent at vel127 duration 500ms, but it seems that vel/time from fiddle~ can not be ignored.

As for piezo trigger I need just a single bang. The difficulty is that after a hit piezo will ring some time(about 1 sec) and rather wildly at first and slowly fades out. However the ringing is very jumpy that makes gating difficult. The only solution I can think of to accumulate the peaks at interval of lets say 100ms and ignore the rest.

Hi.
I am working on the project where I need to transpose a sound file to MIDI and adc~ input(piezo) to detect a hit and from that play the currently active note. Like you have a MIDI track running silently and you make the note sound when you hit a trigger.
I have been successful with the transposing part using fiddle~ and could make a trigger with bonk~ but I am not able to find a way to switch the notes on/off. So far the notes are played as soon they are arriving from makenote~.
So how to put a switch between makenote~ and noteout~?
If I could get an advise for detecting piezo peacks as well. Piezo is a bit tricky device. It rings like a bell when hit and some kind of accumulative value to make a trigger would be ideal.

Get yourself this app
https://www.snoize.com/MIDIMonitor/
And check what messages are sent.
For testing I would use SimpleSynth
http://notahat.com/simplesynth/

FM8 can be tricky to use CC for choosing instruments.

Thanks anyway to help me get this to work / whatever the reason was.

For mac the most versatile option is iSight camera module taken out of the iMac 2005(actually all white iMacs). It is a USB camera that works with mac native drivers. It needs soldering standard USB cable - wires are matched color-coded. I have made several units for my interactive installations and it is very easy to do really.
USB could be extended with active cables easy 25m or use cat5 to USB baluns.
Camera modul from ebay go as low as 3EUR. USB extenders 10/15EUR.
The best thing about this is its small size and obviously it work with mac always.
Look at this list
http://forum.garagecube.com/viewtopic.php?f=1&t=3951&start=105#p26022

very nice indeed

Actually I click on Menu/Put and choose the element(Object in this instance). How would doing "bang" and "dac~" first would make creating "fiddle~" possible or this is not related.

Yes, it does now. But why?

I am rather new to PD. So far I have been learning by tweaking existing projects.
For some things I want to do I need to use [fiddle~] object. What I need to do in order to get it. Simply typing "fiddle~" into object does not do a thing. This is true for all the other extended objects I tried as well.