Playing wav files simultaneously on Uno

Hello guys,
I need some help. :slight_smile:

I can read WAV files from SD with the arduino, and play them. I've connected the buttons on an analog input. I got ten button on two analog channels (So five for each!). It all works! Although I got one problem. It plays small samples, and it has to do them simultaneously. For now I can play one sound, when it's finished then it reads for new input, then you can press the button again to play another sound.
I would like to play the sound, while it looks for another sound. How to fix this problem?

Code: http://pastebin.com/p6YapTnt

Thanks in advance!

Allegedly reading more than one file from an SD card and playback through PWM

But I have not tried this.

Alleged video of such.