Dihydroergotamine is used to treat migraine headaches and cluster headaches. It is not recommended for migraines that affect only one side of the brain (hemiplegic migraine) or the base of the brain /neck area (basilar migraine), or to prevent migraines from occurring.
Pop music is an abbreviation for popular music. In other words, the main difference between pop music and alternative or underground music is the kind of following it has: pop music is usually known by a lot of people and regularly appears on TV.
In the history of music, the term 'pop music' was first used in 1926. It was used to describe 'a piece of music having popular appeal' . Commercially recorded music, consisting of relatively short and simple love songs is known as 'pop music'.