A lollapalooza (n.) means “a remarkable or wonderful person or thing”, which is a term that originated in either 1896 or 1901 from American English, also meaning “a fanciful formation”. Other spellings include: lallapaloosa and lallapalootza.
Google tells us “Lollapalooza is the annual North American alternative pop music concert which started around 1991. It’s a music festival featuring alternative rock, heavy metal, punk rock, hip hop, Electric Dance Music bands, artists, dance and comedy performances and craft booths. It happens in Grant Park, Chicago, IL on Aug 3 – 6, 2017 and has been active for 20 years!”