In 1968, a band known as The Yardbirds decided to change their name to Led Zeppelin and people have commented on the spelling of “Led” ever since. The problem was that the word “lead” (atomic element 82) and the word “lead” (the one in front) are spelled the same way, but pronounced differently and have different meanings. This is an example of a homonym, words that are spelled the same but pronounced differently and have different meanings. The band wanted to play on the idea that they were sure to crash and burn (like an airship made of lead) so, to prevent confusion, the band decided to use the past tense of the verb “lead,” which is “led” and is pronounced just like the heavy metal element.
Wikipedia keeps a list of true homonyms that you can reference.