Digital instrument idea

Planning to build a digital instrument which will play a certain .waw files in accordance with the data coming from pressure sensor.

My question is, how can I store theses .waw files ?

This project will not be connected to a computer, it will be portable. So, somehow I have to store the sound files.
Since I have never tried such thing, have no idea how can I achieve it.
Appreciate if you guide me.

Thank you

I would probably try MP3s over WAVs, but you can store them on an SD card. Look at sparkfun's MP3 Shield: SparkFun MP3 Player Shield - DEV-12660 - SparkFun Electronics