Back 2 You / Still Grey
... that "Back 2 You / Still Grey" was simultaneously the first single by drum and bass band Pendulum to feature either a guest vocalist, or a guest instrumentalist?
... that "<b id="mwFYQ"><a href="./Back_2_You_/_Still_Grey" id="mwFYU" rel="mw:WikiLink" title="Back 2 You / Still Grey">Back 2 You / Still Grey</a></b>" was simultaneously the first <a href="./Single_(music)" id="mwFYY" rel="mw:WikiLink" title="Single (music)">single</a> by <a href="./Drum_and_bass" id="mwFYc" rel="mw:WikiLink" title="Drum and bass">drum and bass</a> band <a class="mw-redirect mw-disambig" href="./Pendulum_(band)" id="mwFYg" rel="mw:WikiLink" title="Pendulum (band)">Pendulum</a> to feature either a guest <a href="./Singing" id="mwFYk" rel="mw:WikiLink" title="Singing">vocalist</a>, or a guest <a href="./Musician" id="mwFYo" rel="mw:WikiLink" title="Musician">instrumentalist</a>?