A connector for securing a guitar to a strap, having a body with an opening and an engagement member slidable within the body. The engagement member has an opening with two portions. The first portion is large enough to receive the anchor post and the second portion is narrow enough to prevent the anchor post from passing through it. The user slides the first portion into alignment with the opening in the body and inserts the anchor post. Then, the user slides the engagement member so that the second portion impedes the release of the anchor post. The body may also have an opening for removal of the engagement member and/or an opening to facilitate sliding of the engagement member. Also there is disclosed a flexible support with one or more connectors and a strap, and a system including connector(s), a strap and a guitar.