no Muslims don't sing songs. When you step in the mosque, it's usually quiet, or you hear low voices of people reciting the Qur'an or doing dua'a. Amd our prayer times are strict on timing. In Arabic it's 'kitaabun mawkoota' ..which means Allah (swt) created the times in a book schedules, whoever misses it or does not pray on time will be treated how Allah (swt) wills in the hereafter. However, i do not pray at bad times only..pray at good times do. How is it fair to ask Allah (swt) to be there for you in your worst times of life, and you are not there for Allah (swt) in your best times of life? so Muslims strictly believe that we should praise Allah (swt) whenever. Because everday life problems occurs mostly from us, Allah (swt) watches... and Allah (swt) created this Earth spacious and perfectly suited for us. So we should praise him back, although it may never be equal to the khair, the goodness Allah (swt) has given us. We pray five most important prayers. In the days of Prophet Mohammed, they would pray to up to 50 prayers! but kind and merciful Allah (swt) eventually lowered it down to too. And some people don't find 5 enough, so they begin to turn the very very early in the morning prayer 'fajr' into a fard prayer.