Rheumatoid arthritis (RA) causes premature mortality, disability and compromised quality of life in the industrialized and developing world (1). Rheumatoid arthritis is a systemic inflammatory disease which manifests itself in multiple joints of the body.
A baritone is the most common type of male voice whose range lies midway between the high tenor voice and the low bass voice. In comedic operas, he is often the leader of the funny business, but he can also be the hero, who sacrifices himself for the tenor or soprano, or the villain.
Other kinds of choirs include strictly male choirs, which can either have the traditional SATB voices with boys singing the upper part (Treble) and men singing the Alto part (Countertenor), or just with 2 Tenor parts, a Baritone and a Bass part (TTBB).