Winning a classical music competition is not just down to the performer's musical prowess, a new study suggests.
An artist's stage presence could be even more important when it comes to evaluating a recital.
The research, published in the PNAS journal, found that people shown silent videos of piano competitions could pick out the winners more often than those who could also hear the music.
It underlines the dominance of our sense of vision, say scientists.
Their study concludes that the best predictor of a winner's musical performance was the visible passion they displayed, followed closely by their uniqueness and creativity.
Chia-Jung Tsay, from University College London, UK, is the study's author and herself a concert pianist. She was interested in how music was judged and found that even professional musicians were unaware of how much they were using visual information over sound.
"I realised that depending on whether audio or video recordings had to be submitted, there could be very different outcomes. This led me to wonder about how much visual information really impacts these important decisions," she explained.
More than 1,000 participants in the study were given samples of either audio, silent video or video with sound, and asked to rate the top three finalists from 10 international classical music competitions.
The actual competition winners were only correctly identified by those who were randomly assigned the silent videos.
When the volunteers viewed video with sound, the accuracy dropped back to chance levels that were found with sound alone.
Dr Tsay said the findings were quite surprising, especially because both trained musicians and those without training had stated that sound was most important for their evaluation.
"Regardless of levels of expertise, we still seem to be led primarily by visual information, even in this domain of music," she said.
"Classical music training is often focused on improving the quality of the sound, but this research is about getting to the bottom of what is really being evaluated at the highest levels of competitive performance.
"We must be more mindful of our inclination to depend on visual information at the expense of the content that we actually value as more relevant to our decisions."
She added that the findings had implications for other areas in life that rely heavily on visual cues, such as hiring employees or selecting political leaders.
Alexandra Lamont of Keele University, UK, a music psychologist, commented on the research.
She said the study supported previous findings that music listeners were often influenced by what they saw during live performances by highly skilled pianists.
She added: "Music performance is far more than just sound, and the visual aspects often enhance the quality of the experience, whether this be watching an energetic young virtuoso on stage at the Menuhin Competition or being dazzled by a light display during a DJ set at Glastonbury.
"Interestingly, participants felt that sound would be the most influential factor in making decisions about performers, so this suggests that we use the dominant cue in making judgements even when it isn't very helpful."
She added that it was reassuring that gender and ethnicity had no effect on judgements, "so it really is all about how the performers played".