Paid to sing? As a professional?
Here's a blog about Chicago Acapella and ChorusAmerica. It's from the director of the group, and their website is here.
In this post, the author discusses a little about the popularity of choral music:
More people participate in choral music in the USA than in any other art form. A full 10% of Americans report singing in at least one choir, based on a recent study from Chorus America. I can only suppose that this fact has some connection to Americans' religious fervor: we attend houses of worship far more regularly, and with far more conviction of belief, than do our counterparts in any Western European nation. We actively "do" our church or synagogue, and we "do" it partly by singing in the choir. Clearly, choral singing is something that Americans love ... 28 million people can't be wrong! Yet very few of us sing professionally in choirs that are all paid.
Here's a little about their pay scale:
Chorus America now defines a professional vocal ensemble as one in which all singers are paid at least triple the national minimum hourly wage. Chicago a cappella pays better than that in rehearsal, and substantially better in performance and recording.