Kyla's I Will Be There (2003) featured English boy band Blue, and Not Your Ordinary Girl (2004) and Beautiful Days (2006) included tracks written by American singer-songwriter Keith Martin.

[6] At age twelve, she auditioned for the television talent show Tanghalan ng Kampeon and won the competition, performing a cover of Jennifer Holliday's "I Am Changing".

While she failed to place in the competition, Kyla caught the attention of producer Francis Guevarra, who expressed interest and submitted her demo tape to music executive Chito Ilacad.

[25] She then recorded the Jonathan Manalo-penned pop song "Tara Tena" for the songwriting competition Himig Handog sa Makabagong Kabataan, where it won first place.

[28] At the 2003 MTV Asia Awards in January, she performed with English boy band Blue, and later collaborated with Irish singer Ronan Keating during the latter's headlining concert at the Araneta Coliseum the following month.

[33] On I Will Be There, Kyla also reunited with boy band Blue for the track "Flexin", and with Valenciano for a cover of his single "Sana Maulit Muli", which won Best Performance by a Duet at the 2004 Awit Awards.

"[35] In support of the album, Kyla headlined an arena concert at the Araneta Coliseum on November 12, 2004, featuring guest performers such as Regine Velasquez, Luke Mijares, and Nyoy Volante.

Media critic Nestor Torre Jr. of the Philippine Daily Inquirer felt she was unoriginal and likened her approach to that of Velasquez, who then-hosted a talent show with a similar format.

[46] At the second Manny Pacquiao vs. Marco Antonio Barrera boxing match on October 7, 2007, at the Mandalay Bay in Las Vegas, Kyla sang the Philippine national anthem.

[54][55] Kyla took on the leading role of a woman coerced into an arranged marriage in the television show Dear Friend: Three Bachelors, co-starring Jay R, Martin Escudero, and Jennica Garcia.

[56] To coincide with her ten-year career milestone, Kyla released Essence of Soul, a greatest hits compilation album issued as a double CD set in July 2010.

[57] During that period, she signed a regional record deal with Indonesian label Tarra Group, which saw her release re-recorded versions of her songs in Bahasa, as well as collaborate with local artists in the country.

[60] She collaborated with singer-songwriter duo Karel and Yosha Honasan for the track "Camouflage", and co-wrote the single "Don't Tie Me Down" with Billy Crawford, Kris Lawrence, Jay R and Jimmy Muna.

[60][61] The writer Pocholo Concepcion from the Philippine Daily Inquirer lauded the album's sound as fresh and innovative, with praise centered on Kyla's collaboration with new and promising musicians.

[65] Also in 2011, Kyla appeared in the dance drama series Time of My Life,[66] starring Kris Bernal, Rocco Nacino, and Mark Herras.

[29] A remake of the 1995 series of the same name, the show is a modernized adaptation of the William Shakespeare tragedy Romeo and Juliet, which tells the story of two teenagers (played by Elmo Magalona and Janine Gutierrez) who fall in love despite being members of feuding families.

Kyla found herself challenged by the idea of playing an unlikeable and manipulative woman, but said that certain aspects of her character's motivation as a mother drew her to the part.

[78][79] The gospel song "Salbabida", written by Jungee Marcelo, was performed by Kyla for the 3rd Philippine Popular Music Festival, where it won the top honor.

A celebration of Kyla's fifteen-year career, the show featured guest performers such as KZ Tandingan, Darren Espanto, and Erik Santos.

[83] Journalists from The Philippine Star praised the concert's production value for its focus on Kyla's career trajectory and musical identity, underscoring her vocals and skill set.

[90][91] The former song featured English rapper REQ, with its accompanying music video directed by John Prats, Sam Milby, and Angelica Panganiban.

[92] In September 2018, she collaborated with Tandingan, Angeline Quinto, and Yeng Constantino for a concert with American vocal harmony group Boyz II Men at the Araneta Coliseum.

[93] Two years later, she co-wrote and recorded "Undeniable" with Jay R.[94] In 2022, Kyla contributed to The Broken Marriage Vow soundtrack with "Init Sa Lamig", a song written by Daryl Ong.

[27] Her musical inspiration varies from R&B singers such as Alicia Keys, Brandy, and Beyoncé to jazz artists like Ella Fitzgerald and Jennifer Holliday,[96] as well as pop rock duo A Great Big World.

[74] During production of her 2002 eponymous album, Kyla cited influences from soul and R&B musicians, including K-Ci & JoJo, Ciara, and Boyz II Men, drawing inspiration for her songwriting.

[99][27] When recording her cover album Heartfelt, she paid tribute to the melodic styles of a variety of artists, including Luther Vandross, Patti LaBelle, James Ingram, and Michael Jackson, describing their music as "classic gems in pop".

[99] She paid homage to Velasquez by performing her song "Pangarap Ko Ang Ibigin Ka" during a co-headlining concert titled Divas: Live in Manila.

[18][19] Ricky Gallardo of The Philippine Star highlights her tone and timbre as particularly distinctive, describing her voice as "strongly remarkable" and "extraordinary", commenting that her vocal range "can easily scale notes and give melodies soulful touches".

[35] Gallardo has compared Kyla's sound to that of American singers Aaliyah and Brandy,[13] while the Philippine Daily Inquirer columnist Mary Ann Bautista likened her to Carey and Beyoncé.

[101] In a review of Journey, The Philippine Star stated, "Her multi-octave range has acquired warmer, fuller tones and she approaches every note with great confidence.