Since the 3rd of march 25 Spotify blocked the apk mod version. What are the alternative music player you would recommend?

To be honest I've never bought into the whole cloud music thing, at the minute I've most of my storage taken up by music and TV on my phone.
I use Neutron music player for music and for video a mix of Stremio and mx player pro.

I have about 500 Gb in my personal library running jellyfin - which I hardly use anymore. I gladly give Tidal $20/month for a family plan, not just for the added value, but because they actually pay for the music, unlike Shitify. The stream quality is even better than about half of my collection. There are other good services and specialty services. Deezer is another. I don't mind helping the artists.

spotube

Personally, I just pirate the FLAC files from RED, and play them with VLC. Several advantages to this:
Spotify is owned by a shitty, greedy company with shitty, greedy practices.
Spotify enforces DRM on almost all its media.
FLAC files have superior quality as they are lossless
I can play them offline without a subscription
Downloads are pretty much instant, as private trackers have insane seeder to leecher ratio
I'm sorry if this isn't the response you're looking for, but as other people have already given recommendations for alternatives, I thought I would just give my 2 cents.
- FYI for everyone, RED is a private tracker
  
  AKA a single point of failure
  
  Fair enough, I forgot to explicitly mention that 😅
  Here's the interview site if anyone wants: https://interviewfor.red/. It's actually quite easy.

auxio for my offline collection (which i've been slowly building so that i don't have to stream anymore)
pipepipe for youtube
- They kept jacking up the prices and making the streaming services worse so I finally pulled the plug and went offline. It's a pain in the ass, to be honest, but once it's all set up it's really quite nice. The only long term issue is discoverability. I feel a bit like I'm stuck with the music I have now and discovering new music and listening to it is such a hassle that I just don't do it. That said, I no longer pay for streaming, and I like what I have, so I'm not complaining.
  I can strongly recommend Plexamp, which integrates well into an existing Plex setup.
  Lidarr is a great complement to an existing Arr stack. And if you're going to host your own music, you might as well look at Sonarr and Radarr, which are so great.
  
  Try https://listenbrainz.org/

Navidrome with tempo if you go the self hosted route

InnerTune uses YouTube music, so far it's been really good. No sign in, no ads, decent quality, and grabs alternative versions like covers and acoustic versions too.
It allows you to download the songs, build a library, create playlists, and you can free listen to related music.
Edit: Corrected typo, it's InnerTune.
- I've been using the fork Outertune, which seems more compatible with youtube music sync across devices, if you care about that
- I only find InnerTuNe not InnerTube. And First time I see this: it refused to work since I installed it from Aurora. And an Innertune (may or may not be the same) from F-Droid doesnt work either
  
  Yup sorry, typo, I corrected it in my original comment. Weird it isn't working for you, I think I have the F-droid version.
  
  tested innertune just now, and it worked. i noticed there are two of them in f-droid, try the other one? or maybe you were being blocked because of vpn? with mullvad only a few countries work with youtube. try rimusic, it uses youtube music too.
- It's asking me to sign in and nothing will play until I do.
  Edit: using the forked version linked on izzyondroid's fdroid repo works fine

I use RiMusic which is Google Music without the adds. You can get it via Fdroid with the IzzyOnDroid repos added. There is also Spotube for all platforms, also available on Fdroid. I haven't had time to try this one out.
- I use RiMusic and love it. I was using ViMusic, but then it got discontinued and I found RiMusic, which is a fork (and I like it better than the original).
- Spotube's Android client had a lot of performance issues last time I tried it (which was a while ago, to be fair) and seemed to be pulling everything from YouTube Music despite the name. I think RiMusic and InnerTune are a lot better, personally. InnerTune if you want a simpler, more traditional UI, RiMusic if you don't mind something a bit more convoluted but also fun and different. RiMusic has some more traditional UI options now as well but I like the older one with the menu on the side - it feels like an app on an early smartphone, back when everything was weird and fun.

Spotube: It's not the greatest UX, but will read your Spotify Playlists and supports offline mode.
- Weird, isn't working for me
  
  I don't know if you tried it or not, but I'd suggest that you install the latest release from their Download Page, as opposed to other sources.
  I've noticed on Android, that the F-Droid Version is not "quickly" updated and frequently breaks due to breaking changes from Google.
  (I've also just upgraded to v4.0 on my android phone and it's working - good luck!)
- jokes aside, spotube's great
- This is what I'm using. I like their playlist generator

I've been using YouTube Music for a long time. I encourage everyoneone to download the Revanced Manager (link here) and mod the original APK (you can download it from anywhere, namely pureApk or uptodown) by yourself. The process is incredibly easy and you can have almost all advantages of premium without paying a penny, like with the modded Spotify APK.

If you like offline music Poweramp on Android is great. Not free tho
- i love the headphone profiles in poweramp!

Youtube Music ReVanced should be good, it's the legacy of Youtube Music Vanced, which has served me well for years, even after its takedown.
- Been using YT music Revanced since summer and it's great. No ads and being able to have my phone off is heaven.
  I really don't get why Spotify people hate YT music and get so elitist about it, it literally has every song to ever exist; if it's on YouTube, it's on YT Music. I especially love it cause videogame OSTs are on there and frequently I see people crying "why isn't it on Spotify?"
  
  As a YTM hater, here are my reasons:
  They closed down Google Play Music, which was an objectively better service, and didn't have feature parity in YTM when they did so. They had promised it, so regardless of arguments towards what it might have now or what features might not be needed because XYZ reasons, they promised that all the features from GPM would be in YTM before GPM was sunset and that was simply not true.
  Maybe this has changed, but at launch, I couldn't "Like" a song to influence my generated playlists without it "Liking" the video on main youtube, which influences my video recommendations. I don't want YouTube serving me exclusively music videos because it sees my YTM Likes and vice versa.

I'm just waiting for a new mod to come out

feishin + navidrome
- Feishin seems to be the best option for navidrome on windows and linux as far as I am aware but I have this really annoying bug that prevents me from seeing any tracks that I don't have marked as favorites for some reason.
  
  I think that is an option. Maybe do you enabled it? Did you try reaching the community through github or discord?

Youtube Music Revanced Extended, using NodeJS Builder on PC. Generally the audio on youtube music feels more alive than on spotify for me. I often experience where the same song has a wider stereo field on yt music, means spotify internally modifies the stereo spread in songs. Also yt music allows louder playback, spotify is stuck with standards that I have no sympathy for. I say if a song sounds good then just let it be, don't generalize all songs.
- I've observed the same thing about YT music's audio. It's actually a bit frustrating because YT has the better quality, it's louder too (Spotify app is strangely quiet in comparison), the algorithm is nicer, I actually even like the UI a little better. But the queue system sucks donkey balls, there's no cross-system control, and no jam so I often go back to Spotify when with friends.

If you're into metal you should check out rokk-app.com. Kamelot's drummer is involved, and they claim to pay artists much more than the alternatives. You can also select a particular band which will get a direct share of your subscription.
It just came out last week so it's rough around the edges for now, but it might be worth checking how it evolves over time.

NewPipe on Soundcloud and look for dj sets

I'm on Deezer with a family plan that my family is happy about ; I use Murglar 2 to download the music I am paying for.
- I should really consider giving money to a spotify challenger, like Deezer.. I guess I'm still too cheap for that

I'm still using Airsonic-Advanced. I know there are alternatives like gonic and navidrome. But, eh. I like buy music from Bandcamp or directly from the artist, and then upload it to airsonic. Works nice.

OuterTune

I use Metrolist (YouTube Music client for Android) and would recommend it.
- thanks I downloaded it.. first time I find an easy download option on github.. I though you had to jump trough hoop to install anything from github. Seems to work fine, thanks a lot
  
  Look into obtainium for downloading apks from github, you can grab it from fdroid

XManager still works fine for Spotify
- Not for me, nor for a lot of other people.
  
  It works fine, you just need to download an old version in order to login. It doesn't let you login in the latest version but you can update it once you are logged in