You of course don't need to work with multidimensional arrays.
But if you'd like to...

if you know how many clips you've got before hand:

int clips = n; //obviously replace n with a number
int[][]audioData = new int[3][clips];

for (int i =0; i< clips; i++) {
 audioData [0][i] = clip id;
 audioData [1][i] = start frame;
 audioData [2][i] = end frame;
}

if you don't know how many clips before hand:

int[][]audioData = new int[3][0]

while (incoming data) {
 audioData[0] = append (audioData[0], clip id);
 audioData[1] = append (audioData[1], start frame);
 audioData[2] = append (audioData[2], end frame);
}

That's all working well -

Code:

audioData[0] = append (audioData[0], clip); 
audioData[1] = append (audioData[1], frameOnData); 
audioData[2] = append (audioData[2], frameOffData); 
 

and I've checked that its putting in the correct data

However, I now want to save this data to a text file, but the following code isn't working. Is it possible to save multi-dimensional data to a text file this easily?

Code:

void keyPressed() {
  if (key == ' ') {
    println("saving");
    saveBytes("numbers.txt", audioData); 
  }
}