I have always considered the term Oldies to apply to pre-Beatles Top 40 tunes. However, my own tastes go back much further.
My personal Top 10 chart is currently comprised of songs from 1926-1932--and it changes periodically. The current #1 song is The Waltz You Saved for Me by Wayne King, which edged out last month's chart-topper Have You Forgotten? by Ted Wallace, now sitting at #2. Both are from 1931.
Fiji, many of my favorite songs are from the Standards era, too, the 20s through 40s and 50s.
PS: I was referring to the radio business category term, “Oldies.” I understand it means different things to different listeners.