Margeotes Fertitta Powell in New York has hired Luca Grelli, formerly of Wieden + Kennedy/Amsterdam, as senior conceptual writer. ... Ian Jeffreys, fromerly of Cilantro Music, has joined New York-based music, sound design and VFX studio Fluid as a music producer. ... HKM has signed directors Siraj Jhaveri and Matt Ogens for exclusive U.S. spot representation. ... Audio engineer and sound designer Brian Beatrice, formerly of Tonic, has joined Bionic Media in New York. ... Stephen Kelleher has joined L.A.-based production and design company Buck's roster of talent.