Turn an Old iPhone or iPad into a Bluetooth MIDI Controller
In this case I'm using KB-1. It requires at least iOS 11, so 'old' here means a 5s/Air 1/Mini 2.
'iPad1' is the old iPad running KB-1, and is the MIDI 'sender'.
'iPad2' is the other iPad running BM3, and is the MIDI 'receiver'.
WITH MIDI OMNI ON (Easy: Use this if you just want to play each Bank without having to setup each Bank's MIDI INPUT):
1.) Turn On Bluetooth on both iPads.
2.) On 'iPad1', open KB-1, tap MIDI (top-right), 'iPad1' should be listed.
3.) On 'iPad2', open BM3, go to BM3 Settings>AUDIO & MIDI DEVICES, tap the Bluetooth icon (top-right), and in the window, click to connect to 'iPad1'.
4.) On 'iPad 2', Turn ON MIDI OMNI.
5.) On 'iPad1' in KB-1, tap OUTPUT (top-middle), select 'iPad2' (the 'receiver').
6.) On 'iPad2' in BM3, load a synth to any Bank on Pad 1. Leave the Banks' MIDI Setup at their defaults. Since MIDI OMNI is enabled, when you select other Banks, they will be played by KB-1.
WITH MIDI OMNI OFF (Advanced: Use this if you want specific MIDI devices controlling specific Banks):
Same as the steps above except:
4.) On 'iPad 2', Turn OFF MIDI OMNI.
6.) On 'iPad2' in BM3, load a synth or keyboard to Bank A1 on Pad 1. Bank A1 MIDI Setup: PORT='iPad1' Bluetooth. Since MIDI OMNI is disabled, you'll have to specify the MIDI INPUT for each Bank.