You never know when gear is going to go sideways on you..! If your show relies on an arranger for any significant part, you can insure yourself from losing those tunes by recording a backing only version, dropping in Markers for oft used restructures, and doing the same on all your SMF’s.
Just about anything from a smartphone to a tablet to a laptop to an old iPod will happily play back audio tracks. You can now do your entire show with whatever keyboard you can lay your hands on if your main axe goes down. Heck, you can get by in a pinch with just a mic and your tracks, push comes to shove! 🎹😷😎
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An arranger is just a tool. What matters is what you build with it..!