Marty Grosz began his life on shaky ground in Berlin on Feb. 28, 1930.

His father, German expressionist painter George Grosz, had been deemed an enemy of the state for opposing the Nazi party. The boy was only 3 when the artist packed up the family and moved to New York. “He saw the writing on the wall,” his son says.

As a teenager, Marty Grosz fell in love with American music, and soon was playing guitar in jazz bands. But while living in Chicago in the 1970s, he came to realize that the upbeat, pre-World War II jazz that he calls “Hot Music” had grown hopelessly unfashionable.

“I was getting really depressed and desperate,” Grosz recalled, sitting on the couch in his Center City rowhouse last week, his 1928 Gibson L5 by his side, his cat Schmutz on his lap.

“I was wondering, what the hell could I do?” he said of his mid-40s crisis. “The music had changed. And I felt — and I think rightly so — that I was too old to change with it.”

So he didn’t. And more than four decades later, it’s clear he made the right decision.

On Wednesday at the Lounge at the World Cafe Live, the still-active, much-loved guitarist, singer, and “jazz comedian” will be feted at what is billed as Marty Grosz’s 90th Birthday Bash, if a few days late.

His autobiography, It’s a Sin to Tell a Lie: My Life in Jazz, is being released by Golden Alley Press, and will be on sale at the venue. The guest of honor will be joined by Philadelphia musicians who back him regularly at venues like the Mermaid Inn in Chestnut Hill, as well as such out-of-town luminaries as multi-instrumentalist Vince Giordano.

For this interview, he wore a scarf looped around his neck and a beret on his head. On the coffee table was a reproduction of a drawing sent by a German art gallery, hoping he’ll help authenticate it as a George Grosz original. (He thinks it’s a fake.)

As a musician, Marty Grosz has always stayed true to himself. He’s kept doing what he has always done: playing his acoustic guitar — never plugged in to an amplifier — and performing sprightly music that aims first to entertain, often inspired by heroes like pianist James P. Johnson and Fats Waller, in their heyday before Grosz was born.

He was able to keep on, thanks to fellow musicians like Bob Wilber, the late clarinetist who invited him to New York in 1976 to join his Soprano Summit band.

» READ MORE: South Philadelphia's Eddie Lang, the "Father of Jazz Guitar" who died in 1933, lives again at Chris' Jazz Cafe.

In the decades since, Grosz has recorded dozens of albums of his own, including Unsaturated Fats in 1991 and, along with other guitarists, Stringin’ the Blues: A Tribute to Eddie Lang, an homage to the South Philadelphian born Salvatore Massaro, the father of jazz guitar.

Giordano, who won a Grammy for his soundtrack work on Boardwalk Empire, Volume 1 in 2012, has often worked with Grosz, starting with Rhythm For Sale in 1996. On Wednesday, he’ll bringing his tuba and baritone sax with him from New York.

“He’s Mr. Hot Jazz,” said Giordano, 67. “He loves a lot of the same music that I do, from the Jazz Age, when jazz was popular music. Marty is a devotee of that kind of jazz that was freewheeling, and so fun and exciting.”

Giordano calls his friend, who has lately given up bow ties for ascots onstage, “a unique personality. Most jazz performers are not communicative. But Marty is a real showman.”

Grosz’s guitar, Giordano said, “uses this unique tuning that these guys like Carl Kress and Dick McDonough came up with in the early ‘30s. It has its own sound.” (Grosz keeps a picture of Kress pinned to his kitchen wall.)

Grosz brought his father’s ukulele to school when he was 7. He never mastered it but caught the music bug as a teenager when he heard Waller, Bessie Smith, and Benny Goodman on the radio.

“I saw Ellington on Broadway,” he recalled. “The big bands would come to the movie houses, and you’d see Benny Goodman, and a movie, and there was still vaudeville then. So you’d have to witness a bicycle act, some guys on unicycles or something, before you could see the band.”

He waited for the guitar player to get a spotlight.

“I liked those moments when you heard the guitar player in a big band," he said. "They didn’t do it that much — mostly they just played rhythm, which is also fun. I’m one of the few guys who likes to do it. Everybody want to be a virtuoso, you know? Not all musicians have taste.

“But I like that part when everybody shuts down and all the instruments drop out” — he sounds out a walking bass line — “and then the guitar comes in. It was a nice moment, I thought.”

Conversation with Grosz veers in a variety of directions.

He was drafted into the Army while at Columbia University in the 1950s and stationed at the prison filled with Nazi war criminals where Adolf Hitler wrote Mein Kampf. His father died in Germany in the 1950s, falling down a flight of stairs. “He was getting into the sauce,” Grosz said.

In 2006, he moved to Philadelphia, where his son, a University of the Arts grad, lives. The two men took care of Grosz‘s wife, Rachel, an educator and clarinet player who had Alzheimer’s disease, until her death in 2012.

Joe Plowman, 28, has been playing bass with Grosz since 2015. “A total kick,” as he put it. Plowman’s interviews with Grosz are included in It’s a Sin to Tell a Lie, which his family’s Emmaus, Pa., company is publishing.

“He has a generally photographic memory and let’s just say an acerbic wit,” said Plowman, adding that Grosz is rightly regarded as a great rhythm guitarist. “His beat is amazing, just his internal sense of time. His sense of swing is immaculate. It’s always lively, always happy. And also, he never ever changed. It’s not the story of someone who evolved. It’s an artist who stayed true to their vision for 90 years.”

Grosz describes his health as good “for a cat my age.” Playing every day keeps his fingers nimble. He moves slowly, yet insisted on climbing stairs to retrieve a book of his father’s artwork.

“It’s how I get my exercise,” he said. “The bad thing is practically everybody I ever played with or knew for any length of time is...“ — he gave the thumbs-down — “... dead.”

What does it mean to be celebrated by fellow musicians as he enters his 90s?

He pondered, then said, “I like to play music. I hope the music is good, and it works. And even if it is, it’s not long enough. It’s over too soon. Because this thing isn’t gonna last forever. I’d like to play music every night, someplace. It’s what I wanted to do all my life.”

Marty Grosz’s 90th Birthday Bash

8 p.m. Wednesday at the Lounge at the World Cafe Live, 3025 Walnut St. $20. 215-222-2400.