I believe that anyone can sing. I have helped several students improve their singing via technical exercises, breathing exercises, solfeges (do-re-mi), and more. In many European countries, singing is a compulsory addition to any instrument learning program as it assists with our inner understanding of pitch as well as rhythm.
I generally teach singing in conjunction with guitar and/or bass guitar lessons and in particular can help with the synchronizing of the two. Sometimes students find it difficult to synchronize their playing with their singing so this is an area that I specialise in, both guitar with singing, and bass guitar with singing.