I'm new to Max and I found a YouTube video that showed me how to use the buffer~ with groove~ and coll (using with an arduino) and I got it to work with one file, but when I try it with any other file it doesn't work. They are all saved in the same place, and they're small (under 1MB) just drum samples. Is there something I need to do when I have more than one? When I click on the first one I did it comes up with the box with the sound waves of the file and on every other one it just comes up with an empty green box. Please help, this is for a project for school.