Love You' takes nearly six seconds to sing. In those seconds the former gospel singer-turned-pop star packs a series of different notes into the single syllable", stated Everitt. "The technique is repeated throughout the song, most pronouncedly on every 'I' and 'you'. The vocal technique is called melisma and it has inspired a host of imitators. Other artists may have used it before Houston, but it was her rendition of Dolly Parton's love song that pushed the technique into the mainstream in the 90s. [ ... ] But perhaps what Houston nailed best was moderation." Everitt said that "[i]n a climate of reality shows ripe with 'oversinging,' it's easy to appreciate Houston's ability to save melisma for just the right moment." Houston's vocal stylings have had a significant impact on the music industry. According to Linda Lister in Divafication: The Deification of Modern Female Pop Stars, she has been called the "Queen of Pop" for her influence during the 1990s, commercially rivaling Mariah Carey and Celine Dion. Stephen Holden from The New York Times, in his review of Houston's Radio City Music Hall concert on July 20, 1993, praised her attitude as a singer, writing, "Whitney Houston is one of the few contemporary pop stars of whom it might be said: the voice suffices. While almost every performer whose albums sell in the millions calls upon an entertainer's bag of tricks, from telling jokes to dancing to circus pyrotechnics, Ms. Houston would rather just stand there and sing." With regard to her singing style, he added: "Her [Houston's] stylistic trademarks – shivery melismas that ripple up in the middle of a song, twirling embellishments at the ends of phrases that suggest an almost breathless exhilaration – infuse her interpretations with flashes of musical and emotional lightning." Houston struggled with vocal problems in her later years. Gary Catona, a voice coach who began working with Houston in 2005, stated: "'When I first started working with her in 2005, she had lost 99.9 percent of her voice ... She could barely speak, let alone sing. Her lifestyle choices had made her almost completely hoarse.'" After Houston's death, Catona asserted that Houston's voice reached "'about 75 to 80 percent'" of its former capacity after he had worked with her. However, during the world tour that followed the release of I Look to You, "YouTube videos surfaced, showing [Houston's] voice cracking, seemingly unable to