This article looks at representations of masculinity in Italian operatic performance in the 1820s and 1830s, with a particular focus on the ways in which male characters were transformed through the practice of aria and scene substitutions. Upon his retirement in 1833, the tenor Nicola Tacchinardi chastised musico performers – women who sang male roles – for their unconvincing portrayal of operatic heroes. Rather than complain about their high-lying voices, he chose to criticise these women's feminine appearance and idiosyncratic stage behaviours as unmasculine. Tacchinardi's criteria for gender performance, then, sidestepped embodied vocality and centred on performer appearance and behaviour in specific narrative situations. My study explores how Tacchinardi and his contemporaries employed aria substitution in heroic roles as a means for plot substitution, forgoing arias of dramatic stasis for dynamic scenes that showcase decisive action and augmented narrative significance. In this pre-Duprez milieu, before the onset of predetermined physiology in operatic discourse, male singers across the 1820s achieved an explicitly masculine self-definition not through voice, but as masters of textual control. Aria substitutions in the operas La Sacerdotessa d'Irminsul, La donna del lago and Norma demonstrate how singers established the components of masculine-heroic conventions through sensitive consideration of dramaturgy. I stress that the singing voice before 1830 was under-assimilated as an index of gender, and that rethinking the history of the ‘rise of the tenor’ may be crucial to understanding the history of the vocalic body.