“We’re very devoted, great friends,” says actor-comedian-director Billy Crystal of Marc Shaiman. “He’s a part of the family. We’ve done all of these things professionally, but we’ve also been through ups and downs as people together.”

The two met in 1984, while Crystal starred in “Saturday Night Live” and Shaiman was a pianist writing special material for the show. Crystal was playing Sammy Davis Jr., Ringo Starr was guest host, and Shaiman helped arrange a funny number in which Crystal sang “Yellow Submarine” while Starr performed “I’ve Gotta Be Me.”

“He was so fast, so quick,” recounts Crystal, “he did a great job and we had a great time. I was touring, and I enjoyed him so much I took him out on the road.”

And when director Rob Reiner cast Crystal in “When Harry Met Sally…,” the actor suggested Shaiman as arranger of the song standards that Reiner was planning to use for the score.

“I kept calling him ‘Rain Jew’ because he knew every romantic song, every love ballad, every funny song,” recalls Crystal. “And he had a great sense of humor that would eventually flourish in movies.”

Crystal, both as producer (“City Slickers,” “My Giant”) and director (“Mr. Saturday Night,” “Forget Paris,” “61*”), has used Shaiman consistently as a composer on his movies. “I trust him. Nobody embraces a joke, or sentiment, or the combination thereof, better than Marc.”

He praises Shaiman’s “broad, crazy, farcical stuff” like “The Addams Family” as well as the music of one of his own films, “City Slickers,” where the score needed to be “funny and poignant, and there are cattle drives, all kinds of instrumentation from harmonicas to Jew’s harps.”

Shaiman is also a principal architect of Crystal’s famous Oscar-night song medleys, and won an Emmy for co-writing the 1992 material. Although many writers contributed ideas, “inevitably it would come down to Marc and I and Bruce (Vilanch), and mostly Marc.”

“He has a great Rolodex of songs in his mind, and his writing ability — the way he can rhyme things musically — is almost scary. They’ve all been very funny, and he knows how to create moments that are very theatrical at the same time. It’s a real gift to be this generation’s Sammy Cahn.”