0 Why Don't Opera Singers Use Microphone

Acoustic of singing

According to acoustic perception, sound are produced by forced of energy that travel through the air. In singing, as in speaking, voice sounds are produced by vocal fold vibrations that interrupt the air stream from the lungs, producing a branch of air pulses. The vocal tract, consist of pharynx and the mouth then stimulate this signal into strong resonance peaks or formants to the spectrum of the singer's sound. 

Why don't opera singers use microphone

The formants of speaking voice and singing voice are quite similar. Except the singing voice, which is produced in such concentration of energy between 2,000 and 3,500 Hz, referred to as the singer's formant, which gives the trained opera singer's voice a "shine" and allows the opera singer to be heard in the presence state of a loud orchestral accompaniment.

Example of one of Wagner's opera

The ride of the valkylies from Wagner's ring cycle, my favorite ;-DDD