Hello, I'm orchestrating the accomp. of a song by me in 2004. The horn 1-2 part sometimes requires a2 note, thus a double stem note. I don't want to write << c4 \\ c >>, since there are dynamics spanner such as \<, and I don't want to add an extra voice to increase the complexity. But could someone help me to create a function to generate double stem on the note and use \stemNeutral to revert?