Echosmith is an American indie pop band formed in February 2009 in Chino, California. The band is composed of four siblings: Graham, Sydney, Noah, and Jamie Sierota. Echosmith started first as "Ready Set Go!" until they signed to Warner Bros. Records in May 2012. They are best known for their hit song "Cool Kids", which reached number 13 on the Billboard Hot 100 and was certified double platinum by the RIAA with over 1,200,000 sales in the United States and double platinum also by ARIA in Australia. The song was Warner Bros.