It's mainly the lower frequencies that are missing or attenuated. 30 Hz to 5 kHz would be great. WWJ and other stations had mobile studios in malls that had audio equalized to 5 kHz, and they sounded pretty good back in the day.
From flypaper.soundfly.com
"During a conversation, the fundamental frequency of a typical adult man ranges from 80 to 180 Hz and that of a typical adult woman from 165 to 255 Hz. Thus, if we look at these three images, the fundamental frequency of most speech falls below the lower edge of the “speech frequency band.”"
Thus, the fourth harmonic of a female voice is barely above 1 kHz. Since the highest note on the piano is 4186 Hz, you could still have voice that sounded good, if not music. Even most fundamental frequencies in music are much less. The only time I think they had that high a fundamental was "Noboby But Me" by the Human Beinz, where they pounded high C a probably a hundred times, and it had enough harmonic content to identify it as a piano note, even on AM radio, at least at the time.
The lowest key on the piano is A 27.5 Hz.
Frequency range of various musical instruments
https://www.zytrax.com/tech/audio/audio.html