Theory Time^® has served public and private music teachers and students since its inception in 1996. The company is located in Missouri City , Texas and is owned by Heather Rathnau and her husband, Ron.

Theory Time^® designs, creates and publishes innovative material for general music theory education. The Workbook Series was successfully introduced at the Texas Music Teacher's Convention in June 1996 and was quickly adopted by teachers throughout Texas, Louisiana, and the southern region. The popularity of this series grew in a very short time, and music companies throughout the U.S. now offer Theory Time workbooks to their customers. Teacher Editions were produced to complement the workbooks. Private teachers, private and parochial schools, home school students and magnet schools are particularly attracted to the extensive reference material, drills, Fun and Challenge Sheets, review tests and self-study features included in the workbooks.

Theory Time^® also serves music educators in public schools. The Reproducible Curriculum Series and complementary Answer Sheets, Fun & Challenge Sheet packets, and "Test Paks" were written for classroom use. The themed Summer Camp Reproducible packets (also used as cross-curriculum study material), Games, Flashcards and other Teaching Aids were also designed to enrich the learning process.

Heather Hearn Rathnau graduated Magna Cum Laude from Baylor University with a Bachelor of Music Degree in Vocal Pedagogy. She also graduated from Baylor with a Master of Music degree in Vocal Performance and Literature. Heather was the recipient of numerous scholarships for piano, academics and vocal performance, in addition to a graduate assistantship in accompanying. At Baylor, Heather was a member of several academic honor societies and was also selected for the national music honor society, Pi Kappa Lambda , which recognizes the highest levels of musical achievement and academic scholarship in colleges, universities and other institutions of higher learning. The international professional music fraternity, Mu Phi Epsilon , also presented Heather its coveted "Sterling Achievement Award" as the outstanding senior Mu Phi student in the nation.

Heather has maintained a successful private studio teaching piano and voice for the past 25 years. She has directed children's choirs at her church, and also served as an adjudicator and clinician for children's choir workshops and seminars on vocal technique. Additionally, she has been the guest soloist for the keynote speaker at the Baptist General Convention of Texas and is a former member of the San Antonio Symphony Mastersingers. Heather is listed in the 2006 Who’s Who in America, 60th Edition and Who’s Who of American Women, 2007.

Heather currently serves as Best of State Chair for the Texas Music Teacher's Association and is an adjudicator for the National Piano Teachers Guild Auditions. She is current President of the Independent Music Teachers Association of Sugar Land, Texas and a long-time member of the Houston Music Teachers Association. She also served as former President of the Forum Music Teachers Association of Houston and former President of the Houston Federation of Music Clubs. Heather is a member of the Texas Federation of Music Clubs where her students actively participate in the National Federation of Music Clubs Gold Cup Festival. Her students have received numerous awards for theory, composition, publication and ensemble at the Texas Music Teachers Association State Conventions. Heather is a native of San Antonio, Texas and, prior to entering Baylor, studied piano under Karl Leifheit, Professor of Music at Trinity University. At Baylor, she studied piano while pursuing her vocal degrees and subsequently studied private voice with Bernadine Oliphint, Professor of Music at Texas Southern University. As a young adult, Heather also spent many hours at the piano with her aunt, Lois Damron Burt, herself a gifted pianist, musician and former private student of David Saperton from the Curtis Institute of Music in Philadelphia. Mrs. Burt was a great inspiration to Heather during her formative years as a musician and helped instill her love of music and desire for excellence. An accomplished musician, author and clinician, Heather has devoted her life to her church, family and music profession.

Ron Rathnau graduated from the United States Air Force Academy and is a former military officer. He is a native of Chicago , Illinois and earned an MBA degree in Finance and Operations Management from St. Mary's University. Heather and Ron have been married 26 years and have two daughters, Alison and Mallory - both alumni of the Theory Time® series.