When was the first arranger keyboard as we know them today launched and what was it?

NOTE: Don’t confuse an arranger keyboard with a single manual keyboard that included the easy play features of organs, (From which arranger keyboards developed) but a genuine arranger keyboard.

Curious

Bill

http://www.casio-intl.com/asia/en/emi/history/




I had one CT-401

bACK IN THE 80'S I had an ELKA X 705 that was an arranger synth and b3
all rolled up into one. I used it for years but then went for early
yamaha psr fold down lid arrangers.
the elka was a beast and I used a 910 lesle speaker that also weighed a
ton.

mel

The Casio you mention is just an easy play single keyboard organ, and the Elka is a portable organ, I am looking for an arranger keyboard as we know them today. (Which includes Orchestrated styles, One Touch Settings etc.?)
Bill

the elka had a complete auto accompanyment section and programable presets plus complet drum machine and manual or foot bass plus programmable synth built in so maybe it was an arranger organ. I just loved it but couldn't carry it anymore

MEL

The first full blown arranger I saw was by Cavendish Organs just before they went under. I forget the model but was around the time of the TP250 organ. I am guessing around 1986? Silver with on board multitrack midi sequencer (step time or real time) which was unusual at the time from memory. However I think Solton pioneered arrangers with the Disco 64 followed by this:
https://www.youtube.com/watch?v=TYN5dlVqFrI