Question: what does Echosmith and Guster have in common?

Context paragraphs:
Guster: Guster is an American alternative rock band from Boston, Massachusetts.  Founding members Adam Gardner, Ryan Miller, and Brian Rosenworcel began practice sessions while attending Tufts University in Medford, Massachusetts, and formed the band in 1991.  The members met during the freshmen Wilderness Orientation program in August of that year, playing publicly together as a trio two months later at the Midnight Cafe coffee house set in the common area of the Lewis Hall dormitory.  While attending Tufts, the band lived at 139 College Avenue in Somerville, Massachusetts.

Echosmith: Echosmith is an American, Corporate indie pop band formed in February 2009 in Chino, California.  Originally formed as a quartet of siblings, the band currently consists of Sydney, Noah and Graham Sierota, following the departure of eldest sibling Jamie in late 2016.  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 also double platinum by ARIA in Australia.  The song was Warner Bros.  Records' fifth-biggest-selling-digital song of 2014, with 1.3 million downloads sold.  The band's debut album, "Talking Dreams", was released on October 8, 2013.

Supporting paragraphs: Echosmith Guster
Answer: band