The cause was a heart attack, said her longtime manager, Lynda Wells. Miss Andrews had recently completed a four-week engagement playing herself in the revue 'Swingtime Canteen' at the Blue Angel in New York. Ms. Wells said that Miss Andrews had agreed to return to the show in December.
Miss Andrews was a teen-ager when she, her older sister, LaVerne, who died in 1967, and her younger sister, Patty, formed the trio whose close-voiced, enthusiastic style became the vocal parallel of the big bands of the swing era. They became stars almost overnight in 1937, singing English lyrics to the Yiddish song 'Bei Mir Bist du Schon.'
That success started the sisters on a long series of novelty hits that included 'Ti-Pi-Tin,' 'Hold Tight,' 'The Jumping Jive,' 'Beer Barrel Polka,' 'Boogie-Woogie Bugle Boy' and 'Apple Blossom Time.'
'The Beer Barrel Polka' was followed by 'The Pennsylvania Polka' and 'Strip Polka,' while 'Rhumboogie' started them on a series of boogie-woogie hits that included 'Beat Me, Daddy, Eight to the Bar' and 'Boogie-Woogie Bugle Boy.'
Their big hits during World War II were 'Don't Sit Under the Apple Tree' and 'Rum and Coca-Cola.'
To a nation at war, the Andrews Sisters became a cherished American institution. They could be heard on the radio, on jukeboxes and on movie soundtracks. They made numerous appearances at war bond rallies and they entertained troops, who seemed to regard them as the epitome of American innocence.
The innocence may have been even more authentic than it seemed. Miss Andrews said it was not until years later that she learned that the sly references to 'working for the Yankee dollar' in 'Rum and Coca-Cola' were suggestive of prostitution in Trinidad.
One of their few ballad hits was the song 'I'll Be With You in Apple Blossom Time,' which was recorded in 1940 and became Miss Andrews's personal favorite.
The sisters' singing style came naturally to them. 'We couldn't read music,' Maxene once explained. 'But when we heard a song, we heard it in harmony.' The sisters became a favored vocal accompaniment to Bing Crosby, who recorded more than 40 songs with them, several of which became gold records.
Maxene, known as Mackie to her family and friends, was born on Jan. 3, 1916. She organized the trio in 1932, when she was 16. LaVerne was 21 and had been studying piano, while Patty, 14, was the tap-dance champion of Minneapolis, where the sisters were born. From the start, LaVerne was the low voice, Maxene the high voice and Patty the one in between.
From the late 1930's until the early 1940's, the Andrews Sisters sold more than 50 million records, appeared as themselves in 22 films and frequently teamed with Bing Crosby and Glenn Miller on their radio shows.
Although the public always saw the three sisters together, singing in close harmony, their private lives were studded with fallings-out. The group broke up in the early 1950's when Patty decided to become a solo performer. Maxene made her own debut as a solo act at that time at the Blue Angel but canceled after a few nights because she was still thinking in harmony terms. The sisters came together again very soon, however, and remained together until LaVerne's death.
In 1970 Maxene accepted the position of dean of women at Tahoe Paradise College in Lake Tahoe, Calif.
'I laughed when I was offered the position,' she said. 'All my life I'd been in show business. My schooling was the school of experience. But I had great rapport with young students.'
In 1974 Maxene and Patty made their Broadway debuts in 'Over Here.' The show ran for more than a year, but after it closed, the two never sang together again.
Although they made a joint publicity appearance in 1987 when an Andrews Sisters star was added to the Hollywood Walk of Fame, the two remained estranged, Ms. Wells said yesterday.
In recent years Miss Andrews had pursued an almost full-time career, lecturing, performing in concerts and at nightclubs and, more recently, in musicals. Earlier this year she appeared in 'Follies,' in Houston and Seattle.
Miss Andrews's marriage to Lou Levy, who managed the sister act, ended in divorce in 1951.
In addition to her sister, of Encino, Calif., Miss Andrews is survived by a daughter, Aleda Hunt, and a son, Peter Levy, both of Salt Lake City; by Ms. Wells, whom she adopted and who lived with her in Auburn, Calif.; Steve Sharpe of Los Angeles, whom she considered a foster son, and one grandchild.