This contribution to the proceedings describes a new technique to prepare and measure the lifetime of the first phonon Fock state in diamond using single-photon time-correlated Raman spectroscopy. By using a pair of ultrafast laser pulses of two different colors we can spectrally distinguish the Stokes photons created during the first pulse from the anti-Stokes photons created during the second pulse. Single-photon detection on the Stokes signal acts as a projective measurement preparing the phonon in an energy eigenstate. During the lifetime of the phonon, the second pulse, which arrives after a controllable delay, has a higher probability of emitting an anti-Stokes photon than allowed by classical mechanics. Two-photon quantum correlations between Stokes and anti-Stokes can therefore be used to map the phonon decay.