DeLange drew greater attention after switching to a live repertoire in both regional and national talent shows in Hilversum, the city where most Dutch TV-programs are recorded.

The SCPO's permanent jury team included musicians-music journalists John Smulders and Henk Korsten (Country Gazette).

That same year, she participated in the "Zangfestival der Onbekenden" ("Song Contest of the Unknown") in the Dutch city of Eindhoven.

With her interpretation of Daddy's Hands by Holly Dunn and The Song Remembers When by Trisha Yearwood, she won the contest and got the opportunity to record a demo.

In 1996, DeLange drew the attention from the A&R-manager of Dutch record company BMI Music, Henkjan Smits [nl].

He persuaded her to join the occasional popgroup Wij and they released the single "De Oorlog Meegemaakt" ("Experienced The War").

In 1998 while being a member of the group Cash On Delivery, she traveled to Nashville, US to record her debut album World of Hurt with top producer Barry Beckett.

Tobacco brand Marlboro organised the tour in a manner of promotion and asked famous Dutch singers to cover their favourite artist.

The first single of the album, Livin' on Love (written by Craig Fuller and Gary Nicholson), was released in October and peaked at No.

November saw the release of her sophomore studio album Livin' on Love, which was a musical departure from her debut, leaning more toward pop/rock.

Although there was a good amount of promotion for the album, it could not compete with the success of World of Hurt, hitting its peak at No.

In 2001 DeLange started her Livin' on Love Tour, performing in many theaters and concert halls throughout her home country.

Although "World Of Hurt" was planned to be released in the States, the record labels in America thought the album was too old-fashioned for the zero's.

In 2002, DeLange and her partner Bart Vergoossen [nl], who is the drummer of her live band, went to America for nine months to work on a new album.

During the recording sessions DeLange took a greater creative role in her music, including receiving songwriting credit for the entire album.

At the beginning of 2004, the Dutch section of record company Warner Music was disbanded and Ilse lost her contract.

She began working with producer Patrick Leonard on a new album, which helped with signing a new record deal.

A day after her father's death, on 10 January 2012, she posted an acoustic version of her song Without You on Twitter, which featured on her 2007 live album.

The first single Blue Bittersweet was written as a soundtrack for the Dutch movie "Het Diner" ("Dinner") and charted to No.

On 15 January 2015, it was announced that DeLange would be replaced as a coach for the sixth season of The Voice of Holland by Miss Montreal lead singer Sanne Hans.

DeLange represented the Netherlands, with singer Waylon as The Common Linnets, during the Eurovision Song Contest 2014 in Copenhagen, Denmark.

DeLange was also previously asked to participate, only always declined due to the bad Dutch reputation of the show.

After singer Anouk participated in 2013 and finished 9th, DeLange changed her opinion and saw a chance to promote real music.

On 7 December 2017 it was revealed that DeLange would have a recurring role in the final season of the ABC/CMT musical-drama series Nashville.

During the show, DeLange got the opportunity to perform her song Love Goes On, which also got added to the season's music album.

Artists signed to her label include The Common Linnets' member Matthew Crosby, Joe Buck, Hannah Mae, Anique van Buseck, Jana Mila, and previously Duncan Laurence.

In late 2020, "Arcade" went viral on TikTok, and became the most-streamed Eurovision song on Spotify and charted on the US Billboard Hot 100 the following year.

Recorded in Nashville, this album was made with producer T Bone Burnett and has a roots and americana sound.

DeLange participated with LEA, Nico Santos, MoTrip, Michael Patrick Kelly, Max Giesinger and Jan Plewka.

[15][16] DeLange was one of the five finalists in the Dutch internal selection for the Eurovision Song Contest 2024, where Joost Klein was ultimately chosen.