Franz Gehring, A Dictionary of Music and Musicians (1900)
“ In time speech gave way at intervals not only to singing, but to singing by several voices at once. Later, when the spoken dialogue had been brought into entire subjection to music, as was the case in Italy after the revolution effected in the whole nature of dramatic representation by the rise of opera, not only concerted vocal pieces were introduced into the German Singspiel, but instrumental music and its protégé monody as well. We find the earliest traces of the Singspiel in the German miracle-plays, which were gradually developed outside the churches from the Passions given inside them. ”
