Recent decades have seen a growing body of hyperscanning studies, investigating neural and physiological synchronization during social interactions. Interpersonal coupling has been related to action coordination and emotional states, including empathy and feelings of connectedness. Several of these studies focused on choirs, showing that singing enhances brain synchronization and coupling of physiological processes. In our study, we investigated the artistic consequences of physiological coupling on singing performance. Based on existing literature, we hypothesized that coupling would improve singing quality, specifically through enhanced inter-personal pitch agreement and timing precision. In an earlier study, we asked eight professional singers to repeatedly perform polyphonic Rennaissance music in three spatial arrangements (distant, close, close with physical contact). We showed that physical contact increased coupling of the respiration signals (Lange et al., 2022; DOI: 10.3389/fnhum.2022.928563). We now analyzed the audio recordings and related singing quality in terms of pitch accuracy and timing to the respiration coupling index. Recordings added up to 672 audio files, from which we annotated a total of 64.215 tone events with fundamental frequency measurements and exact tone onsets using computer tools. However, physical contact did not improve pitch accuracy or timing in comparison to singing without contact. Including the data from all spatial arrangements in linear mixed effects models, respiration coupling did not predict singing quality. Results do not correspond to our initial expectations. We conclude that coupling of the respiration signals between professional singers does not influence the artistic quality of their performance – at least not in our setting.