...with today's music being created in so many new ways an arranger kb can only do so much, mostly a scratch pad regarding new younger styles of music and can never compete with what we hear today
....and yet, whether on TV, in a bar or club or concert stage, the configuration we see 99% of the time will be some combination/variation of guitar, bass, drums, and keyboard (throw in an occasional horn or two). And guess what, for your average musically-challenged audience, an arranger keyboard in the hands of a skilled professional can do a fair job of recreating musically what the average bar band is doing. What's missing, of course, is the visual effect. I'd be willing to bet that if you just grabbed three or four scruffy-looking characters off the street, gave them real (but unplugged) instruments and had them 'fake' the instrument parts (lip sync, 'air guitar', etc.), while the actual music was being played by an arranger, 90% of the audience wouldn't be the wiser. Just make sure you play it (the arranger) 75% louder than usual

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But yeah, they will always be a niche market. Not because they aren't accepted by audiences, but because they aren't accepted by professional musicians. There will be the deniers (there always are) but it's a fact - and the sales figures show it.
Bottom line, sure Arrangers are a lot of fun (for some) but as a 'gig' instrument, it's hard for an audience to see ONE guy simultaneously playing 8 orchestral parts without thinking "ummm, something's fishy". Older nursing home residents may not mind but everyone else sure seems to. JMO.
chas