Professional Orchestras Often "Air-Bow" During Live Symphony Performances

In large orchestral performances (especially string sections like violins and violas), musicians who drop a beat, miss a cue, or encounter an absurdly complex passage will routinely "air-bow". They move their bow fractions of a millimeter above the strings in perfect rhythm with the rest of the section. Audience members (and even conductors) can’t visually tell the difference, and the sheer volume of 20 other violins covers the missing audio completely.