Garland possessed a contralto vocal range. Her singing voice has been described as brassy, powerful, effortless and resonant, often demonstrating a tremulous, powerful vibrato. Although her range was comparatively limited, Garland was capable of alternating between female and male-sounding timbres with little effort. The "Richmond Times-Dispatch" correspondent Tony Farrell wrote she possessed "a deep, velvety contralto voice that could turn on a dime to belt out the high notes", while Ron O'Brien, producer of tribute album "The Definitive Collection – Judy Garland" (2006), wrote the singer's combination of natural phrasing, elegant delivery, mature pathos "and powerful dramatic dynamics she brings to ... songs make her the definitive interpretations". "The Huffington Post" writer Joan E. Dowlin called the period of Garland's music career between 1937 and 1945 the "innocent years", during which the critic believes the singer's "voice was vibrant and her musical expression exuberant", taking note of its resonance and distinct, "rich yet sweet" quality "that grabs you and pulls you in". Garland's voice would often vary to suit the song she was interpreting, ranging from soft, engaging and tender during ballads to humorous on some of her duets with other artists. Her more joyful, belted performances have been compared to entertainers Sophie Tucker, Ethel Merman, and Al Jolson. Although her musical repertoire consisted largely of cast recordings, show tunes and traditional pop standards, Garland was also capable of singing soul, blues, and jazz music, which Dowlin compared to singer Elvis Presley.