Nearly 70 years after its debut, it’s fair to say that “My Fair Lady” has stood the test of time. Most recently revived in a 2022 West End run, Alan Jay Lerner and Frederick Loewe’s musical has changed and adapted over the decades to delight new generations with the classic tale of phonetics, love and the rain in Spain. Right now, San Francisco Playhouse has staged a delightful production that keeps the magic and splendor of the original text intact while embellishing the decades-old material with hefty doses of welcome humor and playful subtext. The story revolves around Eliza Doolittle, a poor flower girl with a thick Cockney accent who takes the interest of Professor Henry Higgins, a renowned phonetician, as he sees her speech as a challenge for him to help her overcome. When he takes her under his wing, Doolittle’s father gets wind of it, and the linguistic hijinks ensue. When handling material as beloved as “My Fair Lady,” one must consider its storied past. From its original T...