The spelling of the word "lady" in the phrase "lady the evening" can be explained using the IPA phonetic transcription. The word "lady" is spelled /ˈleɪdi/ in IPA. The letter "a" in "lady" is pronounced as /eɪ/ which represents the diphthong vowel sound of "ay". The phrase "lady the evening" is not grammatically correct and may be a mistake. It is possible that the intended phrase is "lade the evening", which means to load or fill the evening with something.