founding member; initial member
Colloquial abbreviation of 初期メンバー, commonly used for the original members of a music group, band, or similar team.
See also: 初期メンバー
Only two of that band's founding members remain.
We held a reunion with just the original members.
Abbreviation of 初期メンバー (shoki menbā, 'initial member'), with メン from the first part of メンバー.