Thanks to all three of you for this great conversation. As you may remember, members of this group + Darrel Somoza put together (to help in my work) a player to play from point A to point B (it is in 2 parts and seems quite simple) – and it works just fine except that the stop point can be a bit variable. I will check this version out.
Math’s response really set the stage for getting this to work and speaks to your comment on variable stop points, especially for MP3s. I noticed that MP3s are rarely, if ever an exact number to anything less than 3 places after the decimal. If you want to check it out, use Inspect Element on the time rail and scroll up to the span class for “mejs-time-total mejs-time-slider” The only thing that’s on an exact time is “aria-valuetext”.