The actress Ethel Merman (1908-1984) in the musical play Girl Crazy (1930) sang the song “I Got Rhythm” (music by George Gershwin, lyrics by Ira Gershwin) and became an instant star. Merman wrote in her autobiography Who Could Ask for Anything More (1955):
 
It’s been said that I can hold a note as long as the Chase National Bank. I wouldn’t know about the Chase, but I do hold one pretty long. I held a middle C, in ‘I Got Rhythm,’ for sixteen bars.”
 
While Merman said this about herself, it was originally said by another person commenting on her “I Got Rhythm” performance. George Gershwin (1898-1937) is sometimes credited with the line, but there’s no evidence of this and Merman surely would have mentioned Gershwin in print. New York (NY) Times theatre critic Brooks Atkinson (1894-1984) has been credited with the line (supposedly after hearing it from an audience member), but it does not appear in the online archive of the Times. Music critic Henry Pleasants (1910-2000) has been credited with the line, but it’s unlikely that he wrote about Merman as early as 1930.
 
I’ve Got Rhythm: The Ethel Merman Story (1985) by Bob Thomas credits an anonymous 1930 audience member:
 
“After listening to her whirling performance in one show, a member of the audience remarked, ‘She can hold a note longer than the Chase Manhattan Bank.’”
 
 
Wikipedia: Ethel Merman
Ethel Merman (January 16, 1908 – February 15, 1984) was an American actress and singer. Known primarily for her powerful voice and roles in musical theatre, she has been called “the undisputed First Lady of the musical comedy stage.” Among the many standards introduced by Merman in Broadway musicals are “I Got Rhythm”, “Everything’s Coming Up Roses”, “Some People”, “Rose’s Turn”, “I Get a Kick Out of You”, “It’s De-Lovely”, “Friendship”, “You’re the Top”, “Anything Goes”, and “There’s No Business Like Show Business”, which later became her theme song.
 
Wikipedia: Chase (bank)
JPMorgan Chase Bank, N.A., doing business as Chase, is a national bank that constitutes the consumer and commercial banking subsidiary of financial services firm JPMorgan Chase. The bank was known as Chase Manhattan Bank until it merged with J.P. Morgan & Co. in 2000. Chase Manhattan Bank was formed by the merger of the Chase National Bank and the Bank of the Manhattan Company in 1955.
     
9 September 1929, Middlesboro (KY) Daily News, pg. 2, col. 8:
A good singer always tries lo hold a note as long as possible, but a good banker doesn’t.
 
Google Books
Who Could Ask for Anything More
By Ethel Merman as told to Pete Martin
Garden City, NY: Doubleday
1955
Pg. 36:
It’s been said that I can hold a note as long as the Chase National Bank. I wouldn’t know about the Chase, but I do hold one pretty long. I held a middle C, in “I Got Rhythm,” for sixteen bars.
 
3 July 1955, Trenton (NJ) Sunday Times-Advertiser, “Miss Merman” (a review of her book, Who Could Ask for Anything More), pt. 4, pg. 10, col. 6:
It was said of her that she could hold a note as long as the Chase Manhattan Bank. This, she believes, is an exaggeration, although she held a middle C note in “I Got Rhythm” for 16 bars.
 
21 February 1984, Dallas (TX) Morning News, “Ethel Merman: Show business great epitomized Broadway” by Jeremy Gerard, pg. 3E, col. 1:
From the outset, her singing was marked by a kind of giddy excess. In I Got Rhythm, Miss Merman held a note for 16 bars while the orchestra (which included Benny Goodman, Gene Krupa and Glenn Miller) played the melody. Recalling her astonishing technique, New York Times theater critic Brooks Atkinson quoted an audience member’s remark that “she can hold a note longer than the Chase Manhattan Bank.”
 
“When I finished that song,” Miss Merman recalled in an interview years later, “a star as born. Me.”
 
Google Books
I’ve Got Rhythm:
The Ethel Merman Story
By Bob Thomas
South Yarmouth, MA: J. Curley & Associates
1985
Pg. 187:
After listening to her whirling performance in one show, a member of the audience remarked, ‘She can hold a note longer than the Chase Manhattan Bank.’
 
26-28 January 1990, The Times (Trenton, NJ), “Atlantic City: Ethel clone entertains at Harrah’s” by Randy Alexander, pg. D6, col. 3:
“It was George Gershwin who said I could hold a note longer than the Chase Manhattan Bank,” the Merman character says at one point. “I had that special quality. I’m loud!”
(From the one-woman show Call Me Ethel…Meman, That Is—ed.)
 
20 September 2002, The Daily Globe (Ironwood, MI), “Celebrity Cipher” by Luis Campos, pg. 13, col. 1:
PREVIOUS SOLUTION— “She could hold a note as long as the Chase National Bank.” Music critic Henry Pleasants on Ethel Merman
     
New York (NY) Times
A Producer for All Seasons (Also Juggles)
By STEPHEN HOLDEN
Published: January 19, 2007
(...)
Mr. Siegel, who writes the amusing historical commentary, serves as its affable, low-key M.C. Typical of his remarks, on the year 1930: “The night ‘Girl Crazy’ opened, George Gershwin reportedly told Ethel Merman, ‘Never but never go near a singing teacher.’ She had stopped the show as she would every night holding the ‘I’ in ‘I Got Rhythm’ for 16 measures. There were those who said she could hold a note longer than Chase Manhattan.”