Vocals blending well with instrumental tracks

[skim]

Why do karaoke recordings sound like the vocals float separated from the instrumental track?

Is it because the instrumental track is so compressed, and the vocals aren't?

Is it simply gain control?

 

[TexRoadkill]

There are a lot of factors. Here are the main ones-

Quality of the vocals compared to the backing tracks.

Choice of effects and compression on the vocals.

Volume of vocals compared to the backing tracks.