Well let's look at what would happen if all arrangers suddenly disappeared.

Military bands-------------no effect
High school/college bands--no effect
School music programs------no effect
TV Studio Bands------------no effect
Amatuer/Pro Symphony Orch.-no effect
Opera----------------------no effect
Grand ol' Opera------------no effect
Coffee houses--------------no effect
Jazz groups----------------no effect
Rock groups----------------no effect
Hip Hop/Rap groups---------no effect
Country/Western------------no effect
Latin groups---------------no effect
Schlager-------------------Disaster
99% of Churches------------no effect
Talented OMB's-------------no effect
Not-so-talented OMB's------a serious thinning of the herd

Just my take on it.

chas

Oh, almost forgot. Organ trio---Blessing