no sound from the music i add on my slideshow

Hi there Faigenfam,

Thanks for using the Apple Support Communities. I understand the music you’ve chosen for your slideshow isn’t playing as expected in Photos for Mac. I’ll be happy to help with this.

If the music you’ve chosen isn’t playing, quit Photos, then open iTunes and sign in if you have not already. With iTunes open, open Photos again, then select your slideshow music and see if it works as expected. 

If not, try using a different song and see if any will work. That can help isolate the issue to just the song or let us know if there is a bigger issue. Also, verify the song is downloaded and it’s one that you can use with your slideshow. If it’s a song from a subscription service like Apple Music, you may not be able to use that due to copyright protection and similar laws.

As for the how long you want the music to play, click the Duration button, then choose Set a specific display time for the slideshow: Select Custom, then drag the slider to specify how long the slideshow should play. This link can provide more info:

Create and work with slideshows in Photos on Mac

Best wishes.