Hi Stephan,
\relative c' { \afterGrace <cis e>1 d8 <fis, d'>1 }
and
\relative c' { <cis e>1 \slashedGrace d8 <fis, d'>1 }
The relevant property in \slahsedGrace working under the hood is
\temporary \override Flag.stroke-style = "grace"
In order to avoid braces, one can do this in a \tweak, yielding:
\version "2.20"
\new Staff \relative c' {
\afterGrace <cis e>1 \tweak Flag.stroke-style grace d8 <fis, d'>1
}
or with a healthy dose of sugar:
\version "2.20"
slash = \tweak Flag.stroke-style grace \etc
\new Staff \relative c' {
\afterGrace <cis e>1 \slash d8 <fis, d'>1
}
Lukas
