Under the Ottomans, the Azaan for five times prayer was given in 5 different styles. The 5 melodies for the 5 Azaan per day were each specifically chosen for a reason. While the Fajr melody for Azaan is to wake you up and keep the person awake, the Dhuhr melody is the Hijaz style. Asr Azaan is given in the Egypt style and the Maghrib melody is quick because Maghrib is a short period. Since Isha is the last prayer of the day its melody is sad.