...it may be wonderful, but it's an occasional 1920s record mixed in with 1930s and 1940s records and radio shows. Very few actual broadcasts survive from the 1920s; at
http://www.old-time.com/mcleod/ the radio historian Elizabeth McLeod lists these as the only known airchecks from the decade:
*parts of Former President Woodrow Wilson's Armistice Day speech (from WEAF New York)
*several excerpts from 1923-24 New York Philharmonic Symphony Orchestra broadcasts (WEAF)
*the 4/23/24 speech by King George V (BBC)
*the June 1924 speech by Franklin D. Roosevelt at the Democratic National Convention, New York (WEAF)
*the 9/12/24 National Defense Test Day Broadcast (WEAF)
*a speech by Walter Damrosch and performances by the Associated Glee Clubs Of America on 3/31/25 at the Metropolitan Opera House (probably WEAF)
*sections of the 1/15/25 "Victor Hour" (WEAF)
*the 3/4/25 Inaugural Speech by President Calvin Coolidge (WCAP Washington origination, WEAF linecheck)
*the 3/14/25 International Rebroadcast from London (BBC shortwave signal, WJZ New York aircheck)
*various 7/31/25 WEAF aircheck excerpts, including a section of a Billy Jones & Ernie Hare performance.
*the hymns from the 8/9/25 American Presbyterian Church of Montreal church service (prob. CKAC Montreal)
*the 10/19/25 campaign speech by Canadian Premier William L. MacKenzie-King (prob. CKAC)
*excerpts of the 1/1/26 New Years' International Broadcast (WJZ)
*Lindbergh's Return Celebration, from 6/20/27 (NBC, probably WRC Washington)
*excerpts of the 7/1/27 Canadian Confederation Diamond Jubilee Broadcast (CNR Network)
*the 9/22/27 Jack Dempsey-Gene Tunney boxing match (NBC, prob. KYW Chicago)
*several dozen 1928-29 episodes of
Amos 'n' Andy (not WMAQ airchecks per se)
*a 1928 broadcast of
Roxy's Gang (WJZ)
*the 10/20/28 Thomas Edison Special Congressional Medal Presentation (WJZ)
*the 1/12/29 Cascade Tunnel Dedicatory Program (WJZ)
*the 2/11/29 Thomas Edison Birthday Tribute (WJZ)
*the remarks by Eleanor Roosevelt at the annual Seven Colleges Dinner on 11/13/29 (WOR Newark)
...as you can see, it would be a very small collection to base an entire station upon...