n8n.io is great, but not open source.
hydrogen
I use deemon to download my music from Deezer (free account only supports 128kb/s, this is enough for me though).
For the music server I tried both Jellyfin with the Finamp app and Navidrome with the Tempo app on Android.
For desktop app for both I use SonixD/Feishin (crossplatform)
Both where fantastic solutions but I stuck with Navidrome as it was easier to share playlists. (As an URL for non registered users or as public playlist for all registered users)
My setup is as following: Hypervisor: Proxmox VE NAS: TrueNAS Scale (where all music is stored)
1 LXC container with Deemon installed that downloads music in mounted NFS share from TrueNAS
1 VM with Navidrome installed in Docker with the music folder mounted with NFS
You don't have to use such a setup, you can perfectly do this on your existing PC with Windows, MacOS or Linux with DE. Or server OS like Linux with CLI, OpenMediaVault, TrueNAS Scale or unRAID
I use Deemon for automatic music downloading from Deezer (free). Then I stream my music with Navidrome and some Subsonic compatible apps for mobile. I have this setup for over 3 years now and I have 3TB of music ;)
If you just want to download the songs you need, you can use Deemix (I use this Docker image, you can just install it as an application too)
Tip: if you don't want to setup a music server, you can use Syncthing to sync you music and playlists between devices :)
There are a lot of different methodes you could try. I think the easiest is to connect both systems with a (mesh)VPN like Wireguard, ZeroTier or Tailscale. Then you can simply copy stuff over using rsync -a (archive mode) with a cronjob or using special tools like Borg backup, kopia, etc