SCM drums_p = gh_call1 (proc, ly_symbol2scm (instrument_str_.ch_C()));
audio_staff_p_->channel_i_ = (drums_p == SCM_BOOL_T ? 9 : -1 );
if (name_p_)
SCM drums_p = gh_call1 (proc, ly_symbol2scm (instrument_str_.ch_C()));
audio_staff_p_->channel_i_ = (drums_p == SCM_BOOL_T ? 9 : -1 );
if (name_p_)