I tried this once…i was literally just taking shots in the dark…but
When it comes to vocals and synths…everything has to be in tune…a musical instrument you can get away with some dissonance…but with synths you cant…
You or someone else literally have to be pitch perfect…when applying your vocals to a track to complement synths…
Autotune helps a lot…
Also how would i autotune in fl studio 20 ?