It may happen that your audio files sound choppy or cannot be played at all. This is because MP3, like any other file type, can get corrupted in various circumstances. Most of the time, corruption comes from download problems but it can also result from virus infections. This is when an application such as MP3 Scan+Repair comes in handy to fix those issues.
The tool has a straightforward interface that nobody should have problems using it. Moreover, you get several tips to help you find your way. It is good to know that it supports drag-and-drop operations, but you can also add new files by browsing them in Finder. Fortunately, it supports processing file batches, as it will save a lot of time. As you import the items, the tool automatically scans them and shows convenient info and messages about their status. Once you have created your list, you can proceed to fix them.
All in all, MP3 Scan+Repair certainly fixes your music files and makes them playable again. Regrettably, it overwrites the original files, which is always a risk in case anything should go wrong. The product is completely free to use but donations are encouraged. A final tip: there are online tools that can do a similar job.