In jazz literature, «Down Beat» polls established themselves as an authoritative mean to measure any musician’s popularity. If this data is certainly relevant to music historiography, il seems doubtful to use it without any critical approach. This paper intends to interrogate the value of these famous surveys in an empiric way, following the trajectory of a single musician: Toots Thielemans (1922-2016). His career allows to look at over half a century of the polls, but also to address issues related to the ‘miscellaneous instruments’ category, in which this great exponent of the chromatic harmonica used to compete. I will discuss the organizational modality of the polls, as well as the limits imposed on the contemporary scholar by the data available.