I use itunes/ Music, for my music, import songs, make playlist etc. all fine and well.

But what annoying is often, not so often, I have mp3 files, I download from the web, for examples, songs that accompany a book.
and Just want to hear the mp3 ONce.

And I click on this in the FINDER.

They Open and play in Music, all ok, but then Music seem to create a copy, and this remains in Music, of which I have to delete later.. in in LIbrary

Is this a preference I can undo somehow, super annoying. What other software does something like this?

Now I have a new trick, taking the mp3 and dragging onto Quicktime, but hassle, so be nice to double click these to it's default software Music, but not leave a copy in Music.

In my experience, any song that's opened in iTunes/Music, regardless of where its original file is located, is automatically imported into iTunes/Music in addition to being perpetuated in its original location.

Try this: Do a command-I (Get Info) on your files, and under "Open with," navigate to and select QuickTime Player or another app of its ilk.

That should enable you to play your music without importing it into iTunes/Music.

Ok I had thought about that but was almost scared to do it, as I worried maybe then in Muaic/ itunes, things could go haywire, as those are all mp3s alin there, or start opening in Quicktime, but it seems to be ok.

There's an option to "Use this app to open all files like this one," which I assume will affect any mp3s in iTunes/Music.

I don't suggest trying it to find out.

I'd make the change on a file by file basis as needed.

Here's a hint: You can click the file and hit the space bar to listen to it in Quick Look.

That works if you're dedicated to listening, but it's vulnerable to multi-tasking.

If the mp3 is on your desktop, doing anything Finder related will change QuickLook's focus, and you'll have lost your place when you get back to it.

And further, QuickLook can't play through external speakers.

There's actually no easy answer to kevs's question if he wants to listen to the mp3 only once and not save it. Changing "Open with" actually requires more effort than either deleting the file from Music/iTunes or using QuickTime Player and is efficient only if the mp3 is being saved.