The Beam is designed first for TV but can also be used for music.  The Play 3 was designed for music specifically and later with the advent of the Playbar, Playbase and Arc could be used as a surround speaker X 2.

That said most retailers have at least a 15 day return policy (Sonos is even longer). You could audition the speaker for yourself and decide if it meets your standards for music. To be honest I prefer a nice stereo pair for music or in this case a speaker whose sole function is for music in the first instance.

However, I still believe you need to be the final judge vs mine or anyone’s opinion.

Whether or not the Beam is better than the Play:3 for music depends on the listener. But most people would say the Beam is an improvement over the Play:3. The Beam will play music in stereo creating a wider soundstage than a single Play:3. The Beam (Gen 2) will also support Dolby Atmos music from Amazon Music with a future update. And the Beam is just a great overall sound bar for TV audio.

I’d say the Beam is better for music than the Play 3, I ended up with a spare Beam after getting an Arc and am using it as a music only speaker and I’m very happy with it.

If I had a larger space I’d have gone with a pair of One SLs but the Beam sits perfectly on the top of a cabinet and is almost unnoticeable.