All that Gary has said is correct....but you must have a great sounding product as well some are under the assumption that because people are sick and elderly that they won't notice bad music or singing...NOT!
Having a top notch website to provide potential clients is also mandatory in this day and age......showing what you offer, pics, viideos, demo songs, etc. The big money is not in NHS but in private gigs ithat pay 4 to 5 times what a nursing home does if your good enough to play them.......versatilily in this game goes a long way..........singing, playing,Djing, is all part of todays entertainment package to help you aquire any type gig don't be a one trick pony!