Bradley Lehman (born 1964, Indiana) is an esteemed American musicologist, composer, arranger, organist, and harpsichordist currently residing in Dayton, Virginia. He co-founded the Hodel-Lehman Duo alongside trumpeter and flugelhorn player Martin Hodel and actively performs as a church organist. Lehman is particularly recognized for developing the "Bach/Lehman 1722" temperament, a unique interpretation of J. S. Bach's intricate harpsichord and clavichord tunings. This innovative approach was inspired by his analysis of the ornamental frontispiece atop the title page of the Well-Tempered Clavier. Although not the first to explore this hypothesis, Lehman's tuning system gained significant traction within the music community.

His research was presented in a two-part article published in the Early Music journal in 2005, along with further contributions to Clavichord International, BACH: Journal of the Riemenschneider Institute, and various other academic platforms. To facilitate the dissemination of his findings, he established the private imprint LaripS.com to promote the "Bach/Lehman 1722" temperament. In addition to his musical endeavors, Lehman has worked as a technical writer and was previously an app developer/designer. Since April 2020, he has taken on the role of part-time IT consultant at Eastern Mennonite University.

Lehman began his academic journey at Goshen College (1982–1986), where he double-majored in Music and Mathematics, earning a Bachelor's degree. He continued his studies at The University of Michigan, obtaining two Master's degrees in 1992—one in Early Keyboard Instruments from the University of Michigan School of Music and another in Musicology from the Rackham School of Graduate Studies. In 1994, he completed his Doctor of Musical Arts (A.Mus.D) degree in Harpsichord Performance. His principal research focus on "Bach temperament" addresses a significant question in Western musicology: the lack of explicit instructions from Johann Sebastian Bach regarding the tuning of harpsichords and clavichords for his influential work, the Well-Tempered Clavier (BWV 846–893). Since the release of C.P.E. Bach's 1753 manuscript, Versuch über die wahre Art das Clavier zu spielen ("Essay on the True Way to Play Fortepiano"), many scholars have sought to uncover Bach's intended tuning system, with notable contributions from Bach's pupil J. P. Kirnberger, who proposed three temperaments in his 1771 treatise, Die Kunst des reinen Satzes in der Musik ("The Art of Pure Composition in Music"). In the 20th century, German musicologist and composer Herbert Kelletat (1907–2007) emerged as a leading advocate for "Kirnberger III" as the closest approximation to Bach's intentions.

The analysis of visual elements in Bach's manuscripts gained traction in the 1970s, initiated by Herbert A. Kellner (1936–2003), who posited that the seal from Bach's 1722 work contained a mnemonic rule for tuning within its design, akin to the "Guidonian hand" or the "Circle of Fifths." In 1998, German mathematician Andreas Sparschuh from Technische Universität Darmstadt—studying Baroque organ tunings—identified Bach's decorative outline in the Das Wohltemperirte Clavier's first book. Sparschuh presented a paper at the 1999 German Mathematical Society Annual Conference, asserting that each loop in the ornamentation corresponded to ⅕ in the sequence starting from the note A, and he created a recursive tuning algorithm reminiscent of the Collatz conjecture.

Lehman built upon these same decorative curls found above the title of Das Wohltemperirte Clavier, asserting that Bach intentionally crafted an asymmetrical and irregular pattern. He proposed a method for creating a practical diagram for tuning keyboards by ear based on this spiraling figure. His findings were detailed in a two-part article titled Bach's Extraordinary Temperament: Our Rosetta Stone in the Early Music journal (Vol. 33, Nos. 1&2, February/May 2005, Oxford University Press). Following the article's publication, he launched his LaripS.com website, which made subsequent publications and additional resources readily available. Lehman also recorded several albums, both solo and with the Hodel-Lehman Duo, to illustrate the practical usage of the "Bach/Lehman 1722" temperament.

Many harpsichordists, arrangers, and composers have since adopted Lehman's tuning, including:

- Richard Egarr, who featured it in his 2006 2×CD on Harmonia Mundi - Peter Watchorn, who presented a 2×CD on Musica Omnia - Ronald Brautigam, performing on a Paul McNulty "Walter-style" fortepiano tuned to Bach/Lehman - Luc Beauséjour - Vicky Wright with her son, "boy soprano" Parker Wright - Harpsichordists Menno Van Delft, Pieter-Jan Belder, and Siebe Henstra, who released a 2×CD on Brilliant Classics - The Purcell Quartet - The Bach Sinfonia conducted by Daniel Stipe - Zsolt Kaltenecker, who played the solo "Clavitar" on his 2007 jazz album, a CD on R & V Records - Photographer and sound artist Dave Krooshof, who designed a Raspberry Pi device for his synth rack, processing MIDI data through a custom Pd patch - James Pressler at Frog Music Press, a supplier of songbooks for Rodgers & Roland church organs, produced a MIDI-compatible pipe organ sample package.