If you're a church musician, this is a name you know well, even if you don't know how to pronounce it.  (It's surprising how many people don't, so here's a hint:  it rhymes with YOU.)  Proulx wrote hundreds of works during his life, but his most far-reaching impact came in the form of the service music which is ubiquitous in Catholic, Episcopal and many other churches around the world.  You've probably sung his Community Mass or Festival Eucharist, even if you don't recognize the names.  He had a deep understanding of the role of service music in the worship experience, and his gift for bringing contemporary flair and accessibility to solidly traditional structure and technique have done much to maintain musical standards in an era where churches have struggled with the trend to dumb down their musical content.  The Cathedral Singers, the group Proulx formed in Chicago in the 1990s, has recorded extensively and been featured in numerous TV, movie and commercial spots.