Timeline & mp3's >>>simple question

Briefly I’ve looked around for posts regarding mp3’s inserted onto the timeline, however I didn’t find the answer to my question. Which seems simple enuff:
How do you place a complete song (mp3) onto the timeline in it’s entirety w\o having to manually drag the timeline to the end of the song? I don’t think I worded that properly, but hopefully you understand that what I want to do is NOT have to manually extend the frames to meet the end of the mp3. Understand?? I know how to place audio onto the timeline, however it would be a timesaver to know how to complete this task in one simple step.