Q. Do all phones allow programmable ringtones?

Not always, and there is a lot of confusion about that. Older phones, and the majority of phones manufactured for the North-American market before the year 2002 don't offer that feature.

While most phones offer customizable ringtones nowadays, some models block users from adding ringtones themselves in a free, do-it-yourself manner, in some cases because the networks are asking them to do so, in order to force users to buy ringtones from them.