NOTE: Resources on piano can be found at the dedicated Piano Research Guide.
Early Keyboard Instruments
DVD: Early Musical Instruments, by David Munrow
Early Keyboard Instruments: A Practical Guide, by David Rowland
The New Grove Early Keyboard Instruments, by Edwin Ripin
History of the Piano
Giraffes, Black Dragons, and Other Pianos: A Technological History from
Cristofori to the Modern Concert Grand, by Edwin M. Good, 2nd edition
The Pianoforte in the Classical Era, by Michael Cole.
VHS: The History of the Pianoforte: Famous or Noteworthy Instruments
Played by Great Artists: A Documentation in Sound
Electronic Keyboard Instruments
Keyboard Presents Vintage Synthesizers: Groundbreaking
Instruments and Pioneering Designers of Electronic Music Synthesizers, by Mark Vail
Modern MIDI: Sequencing and Performing Using Traditional and Mobile Tools, by Sam McGuire
The MIDI Manual: A Practical Guide to MIDI in the Project Studio, by David Huber, 3rd ed.
Articles about the Organ in Oxford Music Online:
"Organ" in The New Grove Dictionary of Music and Musicians, 2001
"Organ" in The New Grove Dictionary of Musical Instruments, 2013
"Registration" in The New Grove Dictionary of Music and Musicians, 2001
Books about the Organ in the Music Collection:
Understanding the Pipe Organ: A Guide for Students, Teachers, and
Lovers of the Instrument, by John R. Shannon
The Cambridge Companion to the Organ, by Nicholas Thistlethwaite
The Organ in Western Culture, 750-1250, by Peter F. Williams
Organ Syllabus, by the Royal Conservatory of Music, 1999 edition
DVDs about the organ in Educational Technology & Resources Collection
Magazines, Journals, and Annuals Devoted to the Organ
Books about the History of the Harpsichord and Clavichord
A Guide to the Harpsichord, by Ann Bond
Books about Harpsichord Repertoire
A History of Music for Harpsichord or Piano and Orchestra, by John Harris
Treatises
Historical Harpsichord Technique: Developing la douceur du toucher, by Yonit Kosovske
Playing the Harpsichord Expressively: A Practical and Historical Guide, by Mark Kroll
Couperin: L'art de toucher le clavecin (The Art of Playing the Harpsichord), 2nd ed.
Denis Delair: Accompaniment on Theorbo and Harpsichord (1690)
Michel de Saint-Lambert: A New Treatise on Accompaniment with the
Harpsichord, the Organ, and with Other Instruments (1707)
Books and Information about Temperament, Tuning, and Construction
Treatise on Harpsichord Tuning, by Jean Denis
The Harpsichord Owner's Guide: A Manual for Buyers and Owners, by Edward Kottick
Harpsichord Design and Construction, by Evan Kern
Tuning the Historical Temperaments by Ear, by Owen Jorgensen