In the spring of 2006, my friend, the pianist Verona Maier from the Bucharest National University of Music was seeking for a novel subject for her soon to be written doctoral thesis. In the following discussions I asked her if interpreters really know why they chose a tempo or another in scores that present no such specific indications. As "interpretative tradition" and "good taste" were her first handy answers, I replied that I could describe to her, in detail, why we are prone to chose a specific tempo for a specific piece of music - and that our decisions are actually governed by deep cognitive phenomena that I was willing to make her aware of. In the following week I mapped out for her all the time-related perceptual thresholds (see below) discovered and substantiated in the past decades by experimental psychologists and cognitive musicologists.A few months later Prof. Maier was able to produce the first results. She had the patience to notate all the tempi chosen by seven illustrious interpreters of Bach's Well Tempered Clavier and relate these to the cognitive conditioning I had previously made her aware of. First she would chose a specific Prelude or Fugue, make a thorough temporal analysis (both historical and perceptual) and decide which threshold(s) should be better served and which is, from this point of view, the best tempo choice. She would then compare the result with the seven mentioned interpretations and draw the necessary conclusions.In the fall of 2006, Prof. Maier's doctoral thesis received a summa cum laudae and made me wonder if more musicians should be made aware of the perceptual thresholds system that amongst other things constituted the basis of such a fine doctoral dissertation.I will now present a list of 10 facts regarding the way human brain processes (musical) duration. If you previously had no idea about the concepts listed below, perhaps "The music of the Temporalists" might stir your interest.(1.) Isochronous tempi around and below 50 milliseconds (ms) are perceived as a crepitus sensation (crackling) and cannot create manageable rhythmical patterns. (Crepitus threshold.)(2.) Rhythmisation becomes possible only for isochronous tempi whose pulsations last for cca. 100 ms or more. (Rhythmization threshold.)(3.) Human brain cannot place more than one subjective accent in a cca. 200 ms timespan. (Accentuation threshold.)(4.) The perceptual "now" lasts for about 180-200 ms. (Temporal now threshold.)(5.)  The cca. 200 ms duration marks the first timespan that allows for attention shift. (Attention shift threshold.)(6.) The cca. 240-250 ms per pulsation marks the threshold between holistic and note-to-note processing of isochronicities. (Note-to-note processing threshold.)(7.) The cca. 400 ms duration is the first timespan that allows for a sustainable rate of attention shift. (Sustainable rate of attention shift threshold.)(8.) The cca. 600 ms duration coincides with the average rate of human attention shift. (Natural rate of attention shift threshold.)(9.) Starting with cca. 800 ms per pulsation, humans perceive a temporal surplus (or gap) that becomes the dominant feature for pulsations lasting more than cca. 1000 ms. (Temporal gap threshold.)(10.) Isochronous tempi starting with cca. 2000 ms per pulsation become more and more hard to synchronize. (Synchronicity threshold.)All these perceptual thresholds and values (expressed in milliseconds) may sound as many abstractions but when applied to actual music they may help musicologists see what the "temporality" of a specific rhythmical surface is really made of."The music of the Temporalists", the book I announce with this e-mail, presents in an approachable and simplified way all the mentioned thresholds and comments upon their musical implications. Some believe that such knowledge should become part of the theoretical background of every musician.Andrei Pogorilowski