Hi all,
I had played around with the ESP32 last year and had found this library from Earle Philhower III and used it as a Sample-Player in my project.
I moved only a bit of the code from ESP8266 to my ESP32 and was surprised to get it working.
In my project, I used the wavplayer to play and loop a WAV-File from Progmem in variable speed.

Weeks ago I bought my first Teensy and thought that the Audio-Library is able to play WAV-Files in variable speed .. but it cannot.

A workaround could be to modify the player for Soundfonts which is existing in the Audio-Library.
It seems to be a bit of work to transform an SF2 into the right format.

Earle Philhower was able to use the SF2-File directly which works well on the ESP8266.
Could this library, which he optimized for the ESP8266 work with the teensy 3.x too??
Earle hat also created a MIDI-File-Player together with the SF2-Library. ... could be interesting to play back stored (short or longer) MIDI-Tracks.

Who is able to transform this for the Teensy?

As an Alternative, I had created my library for the ESP32 to stretch or compress an existing WAV-File by repeating Samples or dropping Samples
... the code does not support the expected Filter or Reverb! ... only the Pitch works acceptable for Rythem- or Percussion-Loops.

What would be the best option to get cool pitchable Samples in the Audio-Library for the Teensy? Direct SF2-Play or Simple Stretching like I did on the ESP32?