Musculus was one of the co-authors of the Formula of Concord. He was also one of the most remarkable defenders of Eucharistic adoration in early Lutheranism. His main work on this subject is Propositiones de vera, reali et substantiali praesentia, Corporis & Sanguinis IESU Christi in Sacramento Altaris, Francofordiae ad Oderam, 1573 (thesis IX: An adoratio Christi praesentis in coena sit approbanda). He also edited prayer books with the classical hymns for the adoration of the Sacrament. E.g. his Precationes ex veteribus orthodoxis included Lauda Sion and Pange lingua. He died in Frankfurt an der Oder.
^Hardt, Tom G. A. Venerabilis et adorabilis Eucharistia. En Studie i den lutherska Nattvardsläran under 1500-talet. Acta Universitatis Uppsaliensis, Studia Doctrinae Christianae Upsaliensia 9 (Uppsala 1971.) p. 249