{"id":82041,"type":"Song","title":"Three Little Birds(Jmdenver Arrangement)","artist":{"id":58,"type":"Artist","nameWithoutThePrefix":"Bob Marley","useThePrefix":false,"name":"Bob Marley"},"tabTypes":["PLAYER"]}

begin

    try

    PostData := TStringList.Create;

    PostData.Text:= Memo1.Text; // в  мемо содержится  JSON строка


    RESTRequest2.Method:= rmPOST;

    RESTRequest2.AddParameter('ContentType','application/json' );

    RESTRequest2.AddBody(PostData);

    ShowMessage(ResponseBody);

  finally

    PostData.Free;
end;