I have a problem that I am trying to work out without creating unnecessary complexity. What I need to do is have my participants listen to 30, 30 second sound clips. One at a time with them in control of moving from one to the next. In one condition they will just click continue to go to the next song and in the other condition they will be asked 4 scaled response questions after each song. The problem is the 30 clips they listen to need to be a specific 30 songs based on their age. How do I have Media lab record their age and then begin a specific set of songs and scaled responses (or not) with one of my two different conditions? My age range is from 18 to 40 and there are 200 different clips I am selecting from. Each age has a different combination of 30 clips from those 200. The only thing I have come up with so far is to make each age and condition separately and label the conditions "1.18, 1.19, 1.20, 2.18, 2.19, 2.20" and so on. The problem with this is it will create a total of 360 conditions. Any suggestions?