It's a very technical performance, lots of glimpses and witty lines thrown away in a lower vocalregister.
2
A vocalregister is a series of tones which are produced by a certain position of the larynx, tongue and palate.
3
Some later Romanticists, therefore, such as Spohr and Mendelssohn, came back immediately to the comfortable middle register as the real vocalregister of song.
4
People ask whether there are such things as vocalregisters.