Rabbi Henry Shreibman and Lauren Bacall have something in common: They both know the importance of puckering up and blowing.

For Bacall, of course, it was to coax Humphrey Bogart to whistle in “To Have and Have Not.” For Shreibman, it’s the secret to coaxing sounds from a shofar.

“The sound you are trying to make when you blow a shofar is not an extension of a hum,” said Shreibman, the head of campus for Brandeis Hillel Day School in San Francisco and San Rafael. His shofar playing has become legendary in the Bay Area. “You must use your lips.”

And tongue, said Shreibman, who developed his shofar acumen after playing the French horn for 10 years, and after years of blowing trumpet in marching bands during middle school and high school. “You must use your tongue to punctuate the wind coming out of your lips. The lips must be taut to create a buzzing sound that you are trying to contain.”

Shreibman acknowledged he has a huge advantage when blowing the shofar because he mastered the wind instruments as a teenager. “But the emphasis is not on how big a breath you take, but on how tight and crisp the exit point is when the air comes out.”

To understand and practice the basics of blowing a shofar, Shreibman suggested practicing on a mouthpiece from an old instrument, such as a trumpet, which has a fairly large opening. “Each instrument you put to your mouth wants a certain sound to come out of it. You must find it, and you can also make your breath do what the instrument demands.”

And not just instruments. Grabbing a piece of washing machine hose with an inch of circumference around its opening, Shreibman demonstrated his technique — and the sound was melodious. Then he blew into a long aluminum conduit about 3/4 of an inch in circumference. The result was the same.

Sealing one’s mouth on the opening of the shofar — or any wind instrument — is the key to eliciting sound. “You want to focus on the vibration of your lips at the moment they are centered on the mouthpiece.

“Your upper lip should become a tight British lip,” joked Shreibman as he fingered a military-style bugle, “and should be superimposed over your softer lower lip. You also must sustain air smoothly from the gut. Once you’ve found the right mouthing, don’t mess it up, don’t take it off the top lip. Continue to blow.”

Shreibman blows the shofar by holding it gently like a trumpet and square with his mouth, putting the mouthpiece under the middle of his upper lip. People unfamiliar with the trumpet “tend to blow from the corner of their mouth and use their fingers to seal the other side.”

The rigors of blowing the shofar on Rosh Hashanah and Yom Kippur — especially since he denies himself water as well as food for more than 24 hours — demand that Shreibman prepare well in advance. “During the month of Elul, which precedes the High Holidays, one is supposed to play the shofar every day to herald the coming of the Jewish New Year,” he explained. “That’s my practice.”

Practicing is essential for Shreibman, who is especially known for his sustained and mellifluous tikeah g’dolah, the extra-long final note, which his youngest son, David, 14, once timed at 70 seconds. That happened at a retirement center; normally he holds the final notes in the synagogue for just under a minute.

But there’s a reason he was able to go the extra distance. “I am most spiritually moved at old-age homes,” Shreibman shared. “I am able to sustain the long note so well because it becomes a spiritual act. I lose myself in the moment. That’s where I transition myself from trumpet player to shofar blower.”