Signor Olivieri writes (TBC053) that in 1930 he entered the Liceo Musicale di Bologna (since 1942, Conservatorio Statale ‘Giambattista Martini’) to attend the School of Clarinet with Bianco Bianchini (1868-1940), who taught there from 1905 to 1939. Unfortunately, student records of the period 1931-1942 are very incomplete and Signor Olivieri’s name could not be found in the database of the Museo internazionale e biblioteca della musica di Bologna. However, based on the fact that Signor Olivieri was a mature student with considerable experience, he might have been admitted to the second or third year of the course, thus graduating after 4 or 5 years in 1935 or 1936. It seems unlikely that Signor Olivieri graduated after 1936, as in the Altri Scritti (not included in this exposition) he writes that he signed a first clarinet contract in September 1937, one year after moving to Bologna with his wife. Moreover, he should not have been affected by the 1930 reform that raised the duration of the course to 5 years for the Licenza inferiore and 7 for the Licenza superiore (Maione 2006: 63).
 The references to places and local history become relevant once the situatedness of artistic knowledge is taken into consideration.
The Ricordi shop was located in a early XX century building at the corner between Piazza Garibaldi and via Santa Lucia since 1973. It had the largest selection of records in town ranging from Italian pop to contemporary music, as well as stocking sheet music and musical instruments in the upper stories. It remained the meeting point of middle class youth during the Eighties (paninari) until it declined in the early Nineties, coinciding with the acquisition of Ricordi Records by BMG Music (1994). It became a Ricordi Media Store, part of La Feltrinelli group (http://www.ricordicompany.com/it/page/31) between 2008 until its closure in 2010 (Paduano 2010), and has been a Prada store since 2012. See map: https://goo.gl/maps/mAKtmNy4qdz
 Enduro was the first synthetic reed, patented and produced by Arnhold Brilhard 1940. The dwindling supply from France during the war, created the market in the United States for this styrene (Tonalin) reed, of which Signor Olivieri may have heard about. Although synthetic fibres begun to be used in reed production from the Sixties, such as Aramid by Fibracell and Avilar by Bari. Only recently could a sound quality comparable to natural cane be achieved, for instance by Légère in 1998 or Foreman in 2010. Vandoren, leader in the production of clarinet mouthpieces and reeds, only uses natural cane obtained from the giant cane. Arundo Donax is an invasive species, originating from eastern Asia, but probably imported to the Mediterranean already in antiquity (Hardion et al. 2014), mainly to exploit its hollow stems, 3-5 cm thick and 6 m tall.
[a] The photograph shows a rhizome of giant cane. (Perdue 1958: fig. 3). Quite to the point, Deleuze remarks that 'the rhizome includes the best and the worse' (Deleuze and Guattari 1987: 7). The rhizomatic-arborescent structure of artistic research, and of this exposition in particular, is illustrated by 'the delicate inter-twinning of the roots of ten young Scots pine trees.' (De Assis 2018: 33). Elaborating on this diagram, the rhizome (epistemic practice) is an intermediate structure between the pine trees (propositional knowledge) and the earth in which they are rooted (practice). In the photograph of the giant cane, one can notice several roots that broke when the rhizome was extracted from the ground, as well as small roots still clinging to the soil in which they were growing.
 The clarinet bought around 1979 was a Yamaha YCL-34 in B flat. It remained a best-selling clarinet for intermediate students since it launched in 1978 (http://usa.yamaha.com/products/musical-instruments/winds/clarinets/bb-clarinets/ycl-34/). It was discontinued in 2001 and replaced by the more expensive YCL-450 (http://usa.yamaha.com/products/musical-instruments/winds/clarinets/bb-clarinets/ycl-450/?mode=model). The YCL-34 came with a standard CL4C resin mouthpiece (http://usa.yamaha.com/products/musical-instruments/winds/mouthpieces/woodwind/clarinets_series/#tab=feature).
Yamaha begun producing an ABS clarinet for beginner students in the 1990s. The bestselling YCL-255 currently retails on Amazon.com at around 602.00 USD while a used YCL-34 in good conditions can be bought used on Amazon.com for 545.00 USD (http://usa.yamaha.com/products/musical-instruments/winds/clarinets/bb-clarinets/ycl-255/))
Signor Olivieri’s professional clarinets were all Buffet Crampon. In 1994, the company started producing its Green LinE made of recycled grenadilla for advanced students (http://www.buffet-crampon.com/en/saga/our-history).
 Professional refacer Scott Kurzweil is correct to observe that (2013):
What a great many players don’t realize is that most of these common “troubles” (as Erick Brand called them) can be remedied in less than an hour at the bench. The most common problem I run into is a crooked facing, especially on older mouthpieces that have warped or twisted reed tables.
Nowadays however, due to the changes in production quality and price structure that we tried to dramatise with our personal experience, there are probably less clarinet students facing the need to reface their mouthpiece, than there were when Erick D. Brand (1897-1951) wrote his Selmer Band Instrument Repair Manual (1939) or Signor Olivieri begun working on his Trattato. Arguably, another effect of globalisation was to spread awareness, knowledge and expectations around refacing, which in turn, has led intermediate and advanced clarinettists to try refacing themselves or to seek refacing services. This trend is testified, for instance, by the series of articles ‘Mouthpiece Madness’ on The Clarinet (MacDowell and Guy 2012, 2012b, 2013a, 2013b, 2013c, 2014) and the change of perception during the Eighties is registered by how the refacer is referred to in clarinet literature. For instance, Kenneth Stein calls the 'pianoista' a 'reliable man doing custom refacing' (1958: 5), while David Pino already uses the expression ‘artistic craftsman’ (Pino 1980: 15).
 One example for each case:
- Ridenour, William. 2015. The Clarinet Mouthpiece Revealed. YouTube video. Uploaded 14 January. https://youtu.be/aVM9Bahz2NA [accessed 12.6.2019]
- Sax and Clarinet Mouthpiece Work. Yahoo Restricted Group moderated by Keith Bradbury.
https://groups.yahoo.com/neo/groups/MouthpieceWork/info [accessed 12.6.2019]
- Theo Wanne, Mouthpiece Refacing. Website. https://theowanne.com [accessed 12.6.2019]
- MusicMedic.com. E-commerce of woodwind repair supplies. https://musicmedic.com/ [accessed 12.6.2019]
 The reform of conservatories in the Bologna Process irreversibly excluded refacing practice and knowledge from the curriculum (Ministero dell'università e della ricerca 1999).
 Scott Kurzweil emphasises the importance of risk-taking in the learning process:
After I had worked with Jerry Hall for a while learning the basics of mouthpiece measuring, geometry and facing techniques, he told me “You know everything that I know. Now go screw up about a thousand mouthpieces and you’ll be ready”. Needless to say, I learned a great many of the below issues and remedies while destroying those thousand pieces.’ (Kurzweil 2013)
 Italian language enables to follow more closely Michel Foucault’s distinction between connaissance (conoscenza) and savoir (sapere). Departing from the English translation by Sheridan Smith that uses 'knowledge' for both, we use 'knowledge' for 'connaissance' and 'knowing' for 'savoir':
Connaissance refers here to a particular corpus of knowledge, a particular discipline - biology or economics, for example. Savoir, which is usually defined as knowledge in general, the totality of connaissances, is used by Foucault in an underlying, rather than an overall, way. He has himself offered the following comment on his usage of these terms:
'By connaissance I mean the relation of the subject to the object and the formal rules that govern it. Savoir refers to the conditions that are necessary in a particular period for this or that type of object to be given to connaissance and for this or that enunciation to be formulated.' (Foucault 1972: 15, n. 2)
To the binary savoir/knowing - connaissence/knowledge, we superpose Michael Polanyi's binary tacit knowledge - propositional (explicit) knowledge. We will forfeit a discussion, relying on 'the three-phase model of tacit knowledge.' proposed by Harry Collins (2010: 157-71).
However, Foucault and (Collin's) Polany are only our starting point. For both, socialization is what in tacit knowledge cannot be made explicit. This cannot dispel the principle that explicit knowledge remains a quantity to be extracted and transferred, disposing of the tacit as inevitable production waste. The ideology of tacit knowledge is exposed as soon as it drops off the knowledge market.
This conclusion reflects Michael Schwab and Henk Borgdorff’s principles of ‘(1) self-determination – practice can self-determine its own exposition as research; and (2) indetermination – a practice can be anything, that is, there are no criteria to include or exclude something.’ (Schwab 2015: 1), which they trace back to Kant and the Romantic tradition (Schwab and Borgdorff 2014: 13).
 The "comic mystery' (Fo 2014) alluded here is the creation of a Boundary between knowledge ('reason') and knowing ('experience') in § 59 of Kant's Prolegomena:
At the beginning of this note I made use of the metaphor of a boundary in order to fix the limits of reason with respect to its own appropriate use. The sensible world contains only appearances, which are still not things in themselves, which latter things (noumena) the understanding must therefore assume for the very reason that it cognizes the objects of experience as mere appearances. Both are considered together in our reason, and the question arises: how does reason proceed in setting boundaries for the understanding with respect to both fields? Experience, which contains everything that belongs to the sensible world, does not set a boundary for itself: from every conditioned it always arrives merely at another conditioned. That which is to set its boundary must lie completely outside it, and this is the field of pure intelligible beings. (2004:111)
The boundary underlies Kant's epistemology and is the model upon which most inter/disciplinary knowledge is structured. This exposition attempts to show the fundamental continuity of knowing in which the administrative cartography of epistemological regions is substituted by a continuous epistemic landscape of which the arborescent-rhizomatic structure we described previously is part.
[b] One of Fernand Deligny's maps of lignes d'erre ('wander lines') offers an example of this geoepistemology (2015: 232-3).
"Monoblet, November 1976. Background map and tracing, . . . 36.6 cm x 49.7 cm, [inverted]. The background map is a freehand sketch of the kitchen in “Y House” and its furnishings (table and stools at the top, stove and sink at the bottom). The entrance to the room is on the left.
The wander lines are drawn in India ink on tracings superimposed on the background map. They transcribe the movements of the three autistic children while bread is being made. The “eyes” mark the children’s places around the table. The “hands” are recognizable, as well as the strings of saliva (with which one of the children is playing), represented by little wavelets."
 ‘Epistemic practice’ generalises a notion introduced by Karen Knorr Cetina (1999, 2001). A practice becomes epistemic when knowledge emerging from a practice is reapplied to the practice and new things are thus created. The criteria of novelty and supervenience elaborate on the difference between weak and strong emergence (Chalmers 2006, 2008).
[c] Rubin’s Vase (Blom 2010: 264, fig. 4). The shift from a figure-ground opposition to depth of an image is based on Deleuze Frances Bacon
[d] David Chalmers explains strong emergence (2008)