This study addresses the performative efficacy of the Pellegrina interludes’ solo songs because the songs garnered considerable attention during their performance in the Uffizi theater. The sense of wonder, or meraviglia, that the solo songs evoked for spectators was articulated in numerous accounts, in both eyewitness descriptions (usually diary entries by foreign visitors) and in unofficial printed accounts. Indeed, in these accounts the solo songs were typically singled out for special attention, which is striking in light of the relative brevity of many of the descriptions. Conversely, in the detailed Descrizione issued by the Medici court, Rossi rarely addresses audience response in relation to the music’s affective quality (solo song or otherwise), and when he does, he projects an anticipated response, because his booklet (unavailable for the premiere performance) was written before the performances took place. Most interpreters of the Pellegrina intermedi have disregarded the various unofficial narratives, probably because they do not agree in precise detail with Rossi’s account. Thus, unofficial sources have been neglected as a means of providing insight into the aesthetically and viscerally charged sensation of hearing (and seeing) the solo songs performed in the Uffizi theater. In conjunction with Rossi’s narrative, as well as with the Medici-sanctioned musical publication, unofficial sources help to demonstrate that the spectator-auditor’s perception of musical meraviglia was an essential component of the experiential dimension of the songs.