I tried your idea but the mp3 still failed to play. I then created a public GitHub repository called “hbenditsky” and included all the code for the project named Countdown Timer, along with the mp3 file. The program runs and produces a countdown timer on my iPhone. The timer has a Slider which allows me to select a duration up to 60 minutes. I intend it to play the mp3 file at the mid point and then when the counter times out. I would appreciate any further help you can provide. Thanks