Zoellner Quartet
... that Albert Einstein once played violin with the Zoellner Quartet, which earlier had played by invitation for Helen Keller?
... that <a href="./Albert_Einstein" id="mwCmY" rel="mw:WikiLink" title="Albert Einstein">Albert Einstein</a> once played violin with the <b id="mwCmc"><a href="./Zoellner_Quartet" id="mwCmg" rel="mw:WikiLink" title="Zoellner Quartet">Zoellner Quartet</a></b>, which earlier had played by invitation for <a href="./Helen_Keller" id="mwCmk" rel="mw:WikiLink" title="Helen Keller">Helen Keller</a>?