Early Music Guild (EMG) was founded by keen amateur musicians John Gibbs, Jerome Kohl and Randall Jay McCarty, who incorporated the organization with the State of Washington in 1978 under the name "Early Music Guild". Many of the contributors to this collection were founding or early members of the organization.

The original purpose of EMG was to bring to Seattle some international artists who were performing in other west coast cities such as Vancouver and San Francisco, and also to support the many really good early music ensembles that existed in Seattle. At that time there was a passion for early music in the Pacific Northwest. In the early days, EMG was entirely volunteer run.

EMG merged with Seattle Baroque Orchestra (SBO) on 29th June 2010, and in spring of 2017 the combined organization went through a rebranding process, followed in June 2017 by the launch of the organization's new name, "Early Music Seattle" (EMS).

EMS is a presenter of early music, including the Music for the Ages Series, Global Connections, and Seattle Baroque Orchestra. EMS also provides educational programs serving 2,400 students in Seattle Public Schools annually, and more than 100 adult amateur musicians.

In 2022 Early Music Seattle has an accumulation of forty-five years of experience in presenting excellent international performers, and it has been an incubator in the development of a number of other local early music ensembles - including Seattle Baroque Orchestra, Gallery Concerts and the Medieval Women's Choir.

EMS frequently partners with local venues and artists to program innovative and multidisciplinary projects. Artistic partners include Meany Center for the Performing Arts, ACT, Seattle Theatre Group, Spectrum Dance Company, and Seattle Early Dance. Collaborations include Early Music Vancouver, Portland Baroque Orchestra, and Victoria, B.C.'s Early Music Society of the Islands - creating large-scale works performed in Seattle, Portland, Victoria, and Vancouver, B.C.

Lorri Falterman was the first paid staff person at EMG, serving as General Manager from 1986 until 1991, when Maria Coldwell became Executive Director. Maria served until 1999, followed by August (Gus) Denhard in 2000. EMS expects to a new Executive Director in early 2023, and Gus will be transitioning from Executive Director to Artistic Director of EMS.

Seattle Baroque Orchestra (SBO) was founded in 1994 by violinist Ingrid Matthews and harpsichordist Byron Schenkman. The first performance by SBO was on March 11th 1994, at Gethsemane Lutheran Church in Seattle, under the auspices of Early Music Guild. SBO was one of the first "professional affiliates" of Early Music Guild, receiving support services from EMG such as fundraising and ticketing. This was followed by a period of operating as an independent organization, before the orchestra was merged into Early Music Guild in 2010.

Harpsichordist, conductor and composer Alexander Weimann served as Artistic Director of SBO starting in 2015. He is retiring at the conclusion of the 2022-2023 season.