append sequential music, scheme

[Rune Zedeler]

I would really like a nice syntax for appending sequential music.

seqm = \notes {c d e f}
seqn = \notes { \seqm c d e f }

does not yield { c d e f c d e f } but { {c d e f} c d e f}.

what I would like is something like

\seqm + {c d e f}

or

{ \\seqm c d e f}

I know that it could be easily implemented in scheme, but the syntax
would be too hairy: \apply #seq {\seqm c d e f}

Would it also be possible to add information to transposed music,
telling how much the music is transposed?

-Rune