Multi Pads will 'attempt to' follow left hand chords if a parameter called 'Chord Match' is enabled for a particular pad. Different pads in the same bank can have this set individually.
However, even when Chord Match is enabled, they only seem to correctly transpose the notes that are allowed for a given source chord (typically CM7) when that chord type is played.
If you record other notes in the pad, they will not be correctly transposed with chords.
If Chord Match is not enabled, then you can play any notes you like, but the sequence will not transpose with chords.
Although pads with Chord Match not enabled won't change with chords, they will transpose to a new key if you transpose the keyboard.
Yamaha provide basic information about note transposition for Styles in the manuals, but nothing helpful about notes and 'rules' in Multi Pads.
However in practice the 'rules' and notes allowed for a given source chord appear to be similar, but unlike styles, there is no obvious way to 'fine tune' the transposition rule used or the High and Low note limits for pads! I suspect that these settings depend upon the style in use, although I can't say if that is the style in use when a pad is recorded, or when it is used!
For style recording using the source chord CM7, Yamaha manuals say this...
• Use only the CM7 scale tones when recording the Bass and Phrase channels (i.e., C, D, E, G, A, and B).
• Use only the chord tones when recording the Chord and Pad channels (i.e., C, E, G, and B).
I would welcome any information or clarification about this myself! I posted a question on this forum some years ago, but the only reply claimed that MPs with Chord Match enabled, play and match chords for any notes that are recorded, but this does not appear to be the case!
Just try recording a pad with a simple one octave scale starting at C, and then listen to how this plays back with different chords.
It does transpose to match the root chord, but it only matches all notes correctly if a Major7th is played! For example If a CM7 is played all notes are correct, but if you play a C chord, the 'B' in the pad is replaced by a 'C', despite 'B' being a 'legal' note for the Bass, Phrase, Chord and Pad parts for styles.
I usually play safe and record multi pads in the key that I play in, with Chord Match turned off. They then play as I want, but only in that key. However they also play correctly if l transpose the keyboard!
Regards
Ian