I think for an arranger keyboard is too much instrument for a live band. I had played in the past with the real band, and that did not go too well. One day the drummer could not make it to the rehearasal, and they asked me to turn on the drums of my arranger - it was keeping perfect timing, with perfect levels, and I could adjust the volume not too loud. Another time the guitarist could not figure out his part, so I played it with the perfect guitar sound a few times, while hitting the right notes. After a few incidents like this, everyone hated me as their competition. We had performed a few times, but then went our separate ways.

It is good to be able to play by yourself - you do not depend on other musicians, and your backup band is always ready to accompany you. With the decent selection of styles you do not feel constrained by the lack of skill or technique or musical talent by the band members. It is the ultimate in convenience and instant gratification to play a single with an arranger.

However, all of those considerations aside, playing with the band is more fun. The variability which is inherent in having individual live musicians play various instrument parts in a band is something that is missing from the canned accompaniment in an arranger. I would suggest that the next improvement the arrangers can introduce is the controlled variability of style parts - allow the users to control the variation in the rhythm (for drums, bass, and other accompaniment tracks, either together or as a group which typically follows the rhythm). Long time ago Yamaha had something similar - groove and dynamics - controllable at real time. However, they later relegated it to style programming tools, which are not handily available in real time. Another suggestion for an improvement: allow an audio input which will detect the rhythm of the external drum track (e.g. a live drummer), and have the accompaniment slaved to it. This would help inegrate real drums into the arranger setup and introduce the variablity which is afforded by a live band into arranger setups. It would also offer a visual advantage - most of the time the audience will look at whether there is a drummer playing or not to decide if they are seeing a live or a pre-recorded act (I have to work hard to convince my audiences that I am actually playing live in front of them, rather than jockeying midi/MP3 files).

The other thing is when you play with other musicians, there is a sense of synergy, when your playing actually comes together. The interplay between different players' parts produces the result which can not be achieved by one guy playing a keyboard with one pair of hands. The convergence of sound from multiple parts is something which is the arranger musician will never have to deal with (nor enjoy).

I used to perform (and still do sometimes) with a trumpet player, or one or two other instrumental soloists - they have the skill to keep up with the arranger accompaniment tracks. It was not always perfect, but this was truly ejoyable live-play experience form me (and for the audiences, judging by their reception). Although this requires more practice work and coordination than just playing a single, to me this is a great way to produce a live sound with an arranger accompaniment.

Regards,
Alex