Lady Bird was written by pianist and composer Tadd Dameron in 1939. It was first released to the public in 1948. It’s most ground-breaking harmonic feature for its time was its turn around in the last two bars: (Cmaj7 Ebmaj7 Abmaj7 Dbmaj7).
This is a great tune to know, and great for improvising.

Lady Bird Play Along
Videos to learn the melody/changes for Lady Bird