2100 series
... that the 2100 series of the Keihin Electric Express Railway produces a "do-re-mi-fa-so-la-ti-do" tune when its propulsion system starts up?
... that the <b id="mwFrQ"><a class="mw-redirect" href="./Keikyū_2100_series" id="mwFrU" rel="mw:WikiLink" title="Keikyū 2100 series">2100 series</a></b> of the <a class="mw-redirect" href="./Keihin_Electric_Express_Railway" id="mwFrY" rel="mw:WikiLink" title="Keihin Electric Express Railway">Keihin Electric Express Railway</a> produces a "<a href="./Solfège" id="mwFrc" rel="mw:WikiLink" title="Solfège">do-re-mi-fa-so-la-ti-do</a>" tune when its <a class="mw-redirect" href="./Vehicle_propulsion" id="mwFrg" rel="mw:WikiLink" title="Vehicle propulsion">propulsion</a> system starts up?