LilyPond: How to write Two Voices on Violin

``` \score { \new Staff \relative c'' { << { c16 a' b a } \\ { c,2 } >> %\override NoteColumn.ignore-collision = ##t << { c16 a' b a } \\ { c,2 } >> \mergeDifferentlyHeadedOn << { c16 a' b a } \\ { c,2 } >> %\override NoteColumn.ignore-collision = ##t << { c16 a' b a } \\ { c,2 } >> % This is the best \mergeDifferentlyHeadedOn << { c16 a' b a } \\ { c,2 } >> \override NoteColumn.ignore-collision = ##t << { c16 a' b a } \\ { c,2 } >> } \layout {} \midi {} } ```