Huh, didn't know that! Via https://en.wikipedia.org/wiki/Led_Zeppelin#Formation:_1966%E... :

> One account of how the new band's name was chosen held that Moon and Entwistle had suggested that a supergroup with Page and Beck would go down like a "lead balloon", an idiom for being very unsuccessful or unpopular.[21] The group dropped the 'a' in lead at the suggestion of [manager] Peter Grant, so that those unfamiliar with the term would not pronounce it "leed".[22] The word "balloon" was replaced by "zeppelin", a word which, according to music journalist Keith Shadwick, brought "the perfect combination of heavy and light, combustibility and grace" to Page's mind.[21]

It certainly doesn't help that in a rock context, "lead guitar" is very much pronounced with a long e! And one could be forgiven for thinking that a formation of flying things would necessarily have one member in the lead position. I'm glad they had the foresight to keep us from being led astray!