Is it Open Mike or Open Mic?
Answer: The correct spelling is "Open Mike"
Mike is a far more accessible spelling and less open to mispronunciation when read. 'Microphone' abbreviates to 'Mike' as naturally as 'Bicycle' becomes 'Bike'. The brand of ball-point pens — 'Bic' [rhymes with lick] — is a household name and therefore, it is perfectly forgiveable for a newcomer to mistakenly assume that 'mic' would be a homophone of 'Mick'.
It's derivation from the word 'microphone' should be disregarded when considering spelling. One should not assume a first-time reader of the phrase will have knowledge of what the event consists of, and therefore should not expect the reader's mind to draw a connection with the original word 'microphone'.
Furthermore, consider the potential for confusion when the abbreviation is extended to become a verb, such as in the phrase "I am busy miking up the performers". If you use the m-i-c spelling, it is highly likely the reader would read micing as deriving from 'mice', the collective noun for 'mouse' [a small rodent]. Again, basing the verb on the m-i-k-e spelling, avoids a similar problem with the past tense version: "The performer is miked up and ready to speak".
Now consider when the phrase is first encountered not through reading but by being heard in conversation. The prevalence of the name 'Mike' as the shortened form of Michael is so common in English-speaking societies that it is likely they will have come across 'Mike' previously. Ask somebody who is unfamiliar with open mike events to write the word 'Mike' and it is likely they will spell it in the form they are familiar with. The m-i-k-e spelling is therefore more user-friendly when both seen and heard.
Open Mike Events are all about communication and accessibility to the creative arts. Therefore why would you not extend the same concepts to your choice of spelling.
Still prefer the m-i-c spelling? Click here