After more than 85 years of performing, Mickey Rooney still can’t resist a chance to entertain. Even during an interview – on a cell phone from a car headed to a benefit at Disneyland – the MGM film legend breaks into song:

“We’ll take Manhattan, the Bronx and Staten Island, too.” Rooney, who turned 87 in September, sounds just as he did when he played composer Lorenz Hart in 1948’s musical biopic, Words and Music.

By the time Rooney made that film, his popularity was waning. But for several years in the late ’30s and early ’40s, theater exhibitors named him the biggest movie star in the world. His legendary leading lady: Judy Garland.

Now, Warner Home Video has released a deluxe Mickey Rooney & Judy Garland Collection DVD set, featuring the team’s four major MGM musicals: “Babes in Arms” (1939), “Strike Up the Band” (1940), “Babes on Broadway” (1941) and “Girl Crazy” (1943).

“It was fun making them because the music was so good. The lyrics were wonderful. They had great writers,” said Rooney, who appears on the DVDs in new introductions for each film.

Never modest, Rooney is blunt about his impact on MGM: “I helped to build that studio!” said Rooney, who appeared in more than 300 movies and just came back from a 30-city tour of England with his wife and current co-star, Jan Chamberlain.

“He’s Hollywood royalty,” said his eighth wife, who married Rooney in 1978. She’ll act with him in three of his four upcoming films.

Rooney, who last year appeared in Ben Stiller’s “Night at the Museum,” says he won’t retire. “Why not keep going? Why stop?”

He and Garland were the original “High School Musical” stars, the American Idols of nearly 70 years ago, according to historian John Fricke.

“There’s nobody as timeless as Garland. Rooney is up there as one of the half-dozen male talents in terms of versatility,” said Fricke, who provides commentary and text on the DVD collection.

The $60 box set is lavish, including vintage radio broadcasts, an “Our Gang” comedy, a set of lobby card reproductions, a 50-page hard-cover book written by Fricke that documents the films and a fifth DVD with a Rooney documentary and 21 Garland musical numbers spanning 1936 to 1954.

The four Rooney-Garland musicals share a let’s-put-on-a-show theme. The characters’ names change along with the subplots. And as Garland became a superstar in real life, there came a subtle twist:

“There is a lovely evolution in the films,” Fricke said. “In the first film, she is pining for him. In the fourth film, he is pining for her.”

Rooney and Garland were close friends in real life. When Garland began her 1963 CBS TV variety series, she insisted that Rooney be her first guest.

“She’s on record,” said Fricke, recalling a 1967 quote from Garland about Rooney: “He’s the genius who taught me everything I know. I think he’s the world’s greatest talent.”

Rooney says he still misses his old friend, who died at 47 in 1969.

“Judy was actually just something else,” Rooney said. “It’s too bad we lost her, but we can always memorialize her and keep her through these wonderful DVDs.”

Rooney then admits that he is unable to enjoy the films.

“I don’t watch them,” he said. “The memories hurt.”