Listed below are some undergraduate music theory textbooks.
Benjamin, Thomas, Robert Nelson, Michael M. Horvit, Timothy Koozin, and Robert Nelson. *Techniques and Materials of Music*. 7th ed. Australia: Cengage, 2015.
Burstein, L. Poundie, and Joseph N. Straus. *Concise Introduction to Tonal Harmony*. 2nd ed. New York: W. W. Norton, 2020.
Clendinning, Jane Piper, and Elizabeth West Marvin. *The Musician’s Guide to Theory and Analysis*. 3rd ed. New York: W. W. Norton, 2016.
Kostka, Stefan, and Byron Almén. *Tonal Harmony*. McGraw-Hill, 2024.
Roig-Francolí, Miguel A. *Harmony in Context*. 3rd ed. New York: McGraw-Hill, 2020.
Turek, Ralph, and Daniel William McCarthy. *Theory for Today’s Musician*. 3rd ed. New York: Routledge, 2019.