Music, Nasheeds and Nazams

Q: A lot of naatkwan say in there naat "hum ku bulaana Ya Rasullallah" is this permissible?

Q: In songs some words are kufur words (example rab will forget) so if you listen or spell that word, what is the hukum in islam?

Q: I want to know if it is permissible for a Muslim child to learn to play a musical instrument such as the organ (electric piano) through classes at home or at a special centre. There is much talk of how music stimulates creativity brain growth and so on. With this in mind would it be haram to permit him to learn? We don't generally listen to music as a family but sometimes we watch (clean) movies or cartoons that have music in them.
Sometimes our son comes home from school and requests a certain song that he heard on the bus or his classmates singing to be played and we oblige by playing the song a few times on the computer. Is this permissible? Also what about allowing small children to listen to nursery rhymes and Islamic songs which have clean lyrics but also music in them - can they do this?

Q: Can we hear nasheeds with duf (musical instrument)?

Q:

1. Is duff (type of beating drum) allowed in Islam?
2. Is dhikr with duff allowed in Islam?
3. What is a khanqah used for?

Q: I heard that according to Islam it is allowed to play harmonium. Is it also allowed to play piano?

Q:  I would like to know the harms of listening to music unintetionally e.g. shopping centers etc and would there be any sin for this? 

Q: Is playing a naat on the piano permissible?

Q: I would like to enquire about nasheeds / nazms / naats, Is it permissible to listen to these for entertainment purposes, as is common these days? Also if the meaning is not understood vs if the meaning is understood.

Q: Is music allowed in Islam? Also, I would like to know whether Qawali and Naats with music are allowed in Islam.