How can I help my 2 years 10 month old boy to talk, he doesn't talk at the moment, he only sings, he likes music so much, he is always watching music on TV, if I change the channel for him to watch the cartoons, he always change the channel back to music

Then sing your conversations with him!

Do you notice any other problems with his behavior?

Perhaps try getting him involved in other activities other than watching TV. Unplug the TV and leave it off for several days.

Take him outside for walks, look at books together, set a playdate if you have a friend or family member with young children, play singing games with him... such as patty-cake or itsty bitsy spider, fingerpaint with pudding, make playdough together, kick or roll a ball back and forth, color in a coloring book together, build with blocks, etc. All the while you are talking, pointing to things and saying the name, color, shape, number of, etc.

Is this something new or has he never talked.
Asking this because I know a couple with the same issue.
They found out from a doctor that their child could not hear well enough to actually learn to talk but did hear the beat from music. Their child had tubes put in his ears and eventually got better and now only needs hearing aids.