VLAN tagging is used when the router is connected to an Access Point or another router that sends and receives packets tagged with VLAN ids. It won’t help in this scenario (actually might break communication between the router and your device).
Maybe your music software uses broadcasting to find the music players. If that’s the case, it only works when both are on the same subnet (VLAN).
For the printer, if you manually set up printing devices using the printer’s IP address, it can reside on a different VLAN.
BTW, what’s your music streaming software?