I assume you want a repeat barline? The syntax in 2.22 and later would be \bar".|:" .
{
c1 \bar".|:" c1
}
If you don't mind having one at the end as well (the usual format), you
could just use \repeat, i.e.:
{
c1 \repeat volta 2 { c1 }
}
Cheers,
Aleksa Jakovljevic
organist / harpsichordist / musicologist
Montreal, Canada
