choral concertos
... that Dmitry Bortniansky was the most prolific composer of choral concertos, short compositions for unaccompanied voices to be sung in the Divine Liturgy?
... that <a href="./Dmitry_Bortniansky" id="mwDbs" rel="mw:WikiLink" title="Dmitry Bortniansky">Dmitry Bortniansky</a> was the most prolific composer of <b id="mwDbw"><a href="./Choral_concerto" id="mwDb0" rel="mw:WikiLink" title="Choral concerto">choral concertos</a></b>, short compositions for unaccompanied voices to be sung in the <a href="./Divine_Liturgy" id="mwDb4" rel="mw:WikiLink" title="Divine Liturgy">Divine Liturgy</a>?