there are no such as yamaha music school in Doha. I wish there is one ...   Back in Asia you can send you kid/s to Yamaha Music School on the group basic. So far in Doha i only can find piano lesson on one to one basis, which is i found it rather boring if the teacher can't make the class interesting.

i have no idea about guitar lesson ... but the international music school at the back of Lulu Centre offer the lesson. I am sure you can check on that ...