Aside from Rich, Adler's former students include renowned drummers and professionals such as Louie Bellson, Roy Burns, Dave Tough, Sonny Igoe, Alvin Stoller, Sandy Feldstein, Phil Kraus, Miles Hampton, Daniel Perez and Ted MacKenzie.
Born in New York and raised during the Depression, Adler purchased his first snare drum at 13 and learned to play it without formal instruction. Two years later, he landed his first professional gig with a hotel orchestra in Belmar, New Jersey. At 15, Adler began taking formal drum lessons with a professional pit drummer from the Palace Theater, and studied timpani in his high school orchestra. He actively sought the best drum set teachers to develop proper technique.
In a 1985 interview with Modern Drummer magazine, Adler described his own early educational experiences:
"I began to observe the professionals, and I think that was my greatest teacher. I'd go to the Edison Hotel where there were 15 affairs going on at the same time, with 15 bands. I'd watch all the drummers, good and bad, and I began to see similarities and discovered why different drummers who studied with the same teacher played differently from one another. When most drummers see someone who plays great, they feel unhappy and think they'll never be that good. Fortunately, for me, I reveled in it," Adler said.
One of Adler's former students introduced Adler to Rich: "The kid told me Buddy played better than [Gene] Krupa. Buddy was only in his teens at the time and his friend was my first pupil. Buddy played and I watched his hands. Well, he knocked me right out. He did everything I wanted to do, and he did it with such ease. When I met his folks, I asked them who his teacher was. 'He never studied,' they told me. That made me feel very good. I realized that it was something physical, not only mental, that you had to have."
In the same 1985 interview, Adler clarified the extent of his teacher-student relationship to Rich and their collaboration on the classic instructional book:
"I had nothing to do with [the rumor that I taught Buddy how to play]. That was a result of Tommy Dorsey's introduction to the Buddy Rich book. I used to go around denying it, knowing that Buddy was a natural player. Sure, he studied with me, but he didn't come to me to learn how to hold the drumsticks. I set out to teach Buddy to read. He'd take six lessons, go on the road for six weeks and come back. He didn't have time to practice."
"Tommy Dorsey wanted Buddy to write a book and he told him to get in touch with me. I did the book and Tommy wrote the foreword. Technically, I was Buddy's teacher, but I came along after he had already acquired his technique."
"People always ask me to explain about the book. You see, when Gene [Krupa] did his book, he had a rudimental drummer collaborate with him. But Gene didn't play that way. In Buddy's book, we actually teach the way he does things. If you see any of the kids who used Buddy's book correctly, you'll see that they play the same way, technically," Adler said.
According to the liner notes of the instructional video Henry Adler: Hand Development Technique, produced by CPP Media, "[Adler] is best known for his hand building technique which he developed over the years through his keen observation and analysis of other drummers. As a teacher, Adler has the unique ability to isolate what a student must do to eliminate obstacles which prevent him from technically and rhythmically expressing what is felt within. He considers the proper grip and turn to be the foundation upon which all rudiments are built."
To develop his classic instructional system, Adler researched the physics and mechanics of arm, hand, wrist, fulcrum and finger motions, applying these findings to the art of drumming. Known as the "Adler Technique," Adler's rigorous system emphasizes complete ambidexterity, mind-body coordination, elimination of all unnecessary arm or wrist motions, fulcrum muscle development, sight-reading, syncopation and mastery of varied musical styles.
In addition to Buddy Rich's Modern Interpretation of Snare Drum Rudiments, Adler co-authored or published countless instructional books, many of which became instant classics. Among these are 4-Way Coordination: A Method Book for the Development of Complete Independence on the Drum Set by Marvin Dahlgren and Elliot Fin, "Odd Time Reading Text" by Louis Bellson and Gil Breines, The Friese-Lepak Timpani Method by Alfred Friese and Alexander Lepak, and How to Play Latin American Rhythm Instruments, which Adler co-authored with Humberto Morales, F. Henri Klickmann, and Ernesto Barbosa.
In May 2005, Music Sales Corp. published a new edition of Buddy Rich's Modern Interpretation of Snare Drum Rudiments, with revisions by former Adler student and renowned drumming instructor, Ted MacKenzie. According to an official press release issued by Music Sales Corp., MacKenzie's revisions to the classic book include "detailed explanations of the Adler method that were not part of the original edition."
"The revised version of the book retains the rudimental exercises in the original and adds detailed descriptions of the Adler method-the grip, the wrist turn, accents, rebound control and so on. These insights are the foundation of the Adler method, but they were not described in previous editions of the book. The revision also includes expert line drawings and photos that illustrate the fine points of the Adler method. MacKenzie, a long-time professional graphic artist, did these drawings himself."
In 1985 Adler tried his hand at acting and appeared as the Magic Club drummer in the movie Desperately Seeking Susan, starring Madonna and Rosanna Arquette. In 1988 he was inducted into the Percussive Arts Society’s Hall of Fame.
Until his death, Adler served on the Advisory Board of Modern Drummer magazine.