Specially commissioned by German organ builder Laukhuff (still operating) for scaling organ pipes (wood/metal flues & reeds) based on copyrighted design by German Richard Rensch (1923-1997) but preceded by German Wolfgang Adelung’s earlier (simpler) version - extremely complicated to use (cursor extension + graph paper needed for interim calculations) - superb quality but only 500 ever made - Orgelbau-Verlag started selling their own (inferior) version in 1986

Slide chart copyrighted Music Theory Wheel design by Donald L. Erjavec

Slide chart specially commissioned by UK copyright holder Dudely Fulller Associates - design invented by musician Dudley Fuller

Slide chart made for UK patent holder (GB2245409) Peter Davies.

Slide chart (later version) copyright designed & retailed by Co Atpress (“coat press” nickname = pseudonym for Kees Jaspers) for simply finding any chord on any string or keyboard instrument + Kees was a a bassist & member of Dutch bands Down Town Jazz Band, Dixieland Pipers & Dutch Swing College Band

Slide chart copyright designed & retailed by Co Atpress (“coat press” nickname = pseudonym for Kees Jaspers) for simply finding any chord on any string or keyboard instrument + Kees was a bassist & member of Dutch bands Down Town Jazz Band, Dixieland Pipers & Dutch Swing College Band

Slide chart copyrighted design by Martin H. Samuel - later replaced by a phone App

Slide chart design by Victor Leone for accordion playing

Unlike any other Acu-Rule or music type - design copyright Mel McSwain - sole distributor: McSwain Co., Arkansas

Specially commissioned (2500 made) & exclusively sold by German music retailer Verlag Erwin Bochinsky ​(trading name Verlag Das Musikinstrument) + based on earlier prototype by German master piano builder Klaus Fenner for wound & unwound strings + calibrated for imperial & metric sizes + table on back for recalibrating steel core wound strings - part of sundry applications series

Thick plastic construction with copyrighted design by Australian A.B. Packer + later version was duplex blue & white

For constructing chords in any key & transposing one key to any other

Specially commissioned by L.E. Waddington for adjusting relative vibration rates, degrees of scale, intervals, chord structures, scale indications & transposition data against a piano keyboard - based on several standard frequency level specifications - layout © L.E. Waddington - Reference Frequency table in well - Subscript Notation, Instrument tables, Time Signatures & nomograms on back

Specially commissioned by Thomas Specialities for composing, transposing or creating harmonies - layout © Thomas

Slide chart patented (US2079920) design by Thomas J. Ozanda for musical signatures of various major & major keys

Slide chart copyrighted design by Neal F. Mears & promoted as: The Slide-Rule of Music

Slide chart patented (US5386757) design by Daniel Derrick displaying fingering patterns for 6-string rock & blues guitar

​Slide chart for finding sharps & flats for a given key on piano keyboard

Designed by two professional musicians for professional composers/arrangers + supposedly only 5000 ever made

Slide chart copyrighted by Dutch publishers for finding guitar keys (front) & guitar chords (back)

Slide chart copyrighted design & trademarked DIAL-A-CHORD name

Slide chart with copyrighted design by John De Paul designed specifically for Hawain guitar

Design of rule & book by tonal fanatic Llewelyn Southworth Lloyd (1876-1956) as introduction to fundamentals of musical scale​s & intervals - works in the same simple way as Oughtred’s original invention + shows & uses relationship between mathematics & music - slide rule in back

Slide chart copyrighted design published by American Mills Music Inc. ​

Slide chart copyrighted design by Lynn T. Harris for organs, pianos & accordions - surprisingly made by manufacturer better known for its aluminium slide rules

Slide chart designed for constructing chords, transposition and general music theory

​Slide chart for transposing chords & placing guide for a capo on guitar fingerboard + UPC 700682010013 or EAN 0700682010013 barcode numbers - still sold

Post-WWII Amsterdamse Jazz Club was a nightspot for traditional jazz that later became a non-profit foundation for jazz-related projects as this educational slide chart for learning to improvise through choice of chords + developed by musician, game creator & foundation member Fred Hoorn + it was accompanied by a book & cassette of musical examples

Slide chart designed by Gianluca Govoni - still sold

Slide chart with registered designed specifically for Spanish (flamenco) guitar

Dutch language book by Anne Klein Geltink for calculating scales, chords & transposing major & minor chord combinations with a do-it-self scale transposition rule in back ​

Slide chart copyrighted design by American Norton Gross + table chords & chord structure on back

Russian slide chart with revolving wheel for choosing chords

Slide chart for choosing guitar chords

Made for specialist German music publisher Orgelbau-Fachverlag for scaling organ pipes (wood metal flues & reeds) but a follow-on cheaper & thinner version of original limited high-quality Laukhuff Orgelpfeifen model by F-C + Table of frequencies on back

Copyrighted design by Dr. Wolfgang Adelung (1920–1994) using Töpfer's index for scaling organ pipes - Adelung was a well-known German organist who published many books related to building & playing of organs + "simpler" predecessor to limited high-quality Laukhuff Orgelpfeifen model by F-C  

Specially commissioned slide chart by Dutch bell foundry (still operating) Petit & Fritsen + designed by Hien Fritsen to help carillonneurs choose optimum set-up of bells (tones) for carillons of 1-46 bells + on back a table to calculate strength of housing needed for a given bell weight when being rung - see also GB & NL versions

Specially commissioned slide chart by Dutch bell foundry (still operating) Petit & Fritsen + designed by Hien Fritsen to help carillonneurs choose optimum set-up of bells (tones) for carillons of 1-46 bells + on back a table to calculate strength of housing needed for a given bell weight when being rung - see also NL & F versions

Specially commissioned slide chart by Dutch bell foundry (still operating) Petit & Fritsen + designed by Hien Fritsen to help carillonneurs choose optimum set-up of bells (tones) for carillons of 1-46 bells + on back a table to calculate strength of housing needed for a given bell weight when being rung - see also GB & F versions

Designed & copyrighted by American musician Henry E. Pendleton

Slide chart for any instrument for finding 9 most popular chords for 17 different tones + sibling Table D'Accords green version in French also issued