Same situation -- trained musician, excellent ear (I can make those Karaoke backing tracks) - but zero absolute/perfect reference without a tuning fork or tuned

Same situation -- trained musician, excellent ear (I can make those Karaoke backing tracks) - but zero absolute/perfect reference without a tuning fork or tuned instrument. Funny story: Watching "A Hard Day's Night" with my son, when he was around 8 years old: "Daddy, why are the Beatles out of tune?" (The tracks in the movie were slightly off-pitch compared to the album.) Turns out he has perfect pitch. As in, he can start singing a song in the exact pitch he learned it -- close enough to sound in tune with the recording. This is accuracy to the discrimination level of trained musicians -- I estimate about 0.5% or 1/10 of a semi-tone. Oddly, or not, it took him several years to learn to hear music on a relative basis -- to hear C-G as similar to D-A. Transposed songs (Sinatra sings "Something" in F) sounded to him like completely different songs. Now he has developed an excellent musical ear, and taught himself to play bass. relevant: https://www.pianostreet.com/smf/index.php?topic=34782.0 https://www.pianostreet.com/smf/index.php?topic=34782.0