In 2005 Ballard replaced Rossy as the drummer in Mehldau's trio.
This, in the view of critic Ray Comiskey, did not radically change the trio's sound, but it did give them "a harder edge and pushed Mehldau more, with bassist Larry Grenadier left more in a fulcrum role, the centre around which piano and drums cavort."
Another critic, Ben Ratliff, suggested that the new trio's sound was "denser and more tumultuous", with rhythms more overt than with the previous trio.
In February 2005 Mehldau performed in Hong Kong for the first time, with his new trio.
Their first album, Day Is Done, was recorded the following month.

Mehldau continued to expand beyond trio and solo playing.
In the spring of 2005 he premiered a song cycle that he had written for classical music singer Renée Fleming.
This association was based on a commission from Carnegie Hall; their 2006 recording contained music set to poems by Rainer Maria Rilke and Louise Bogan.
Mehldau also collaborated with guitarist Pat Metheny from 2005 – they recorded two albums together that year, along with Grenadier and Ballard, and in 2007 went on a worldwide tour.

Another Village Vanguard recording, Brad Mehldau Trio Live, was recorded in 2006 and released two years later.
This also contained a variety of sources of material, including "Wonderwall" by rock band Oasis, "Black Hole Sun" by grunge band Soundgarden, and Chico Buarque's samba "O Que Será"; "it's business as usual – state-of-the-art contemporary jazz piano", commented Fordham.
A further recording from 2006 was released as Live in Marciac in 2011; this contained two CDs and one DVD of a solo concert by the pianist.
Mehldau asserted that his third solo recording "is the beginning of a freer approach, [...] and maybe [contains] more ease and fluidity in a musical texture with several simultaneous voices".
In 2006 Mehldau also played on saxophonist Michael Brecker's final album, Pilgrimage.

In March 2007 Mehldau first performed his piano concerto "The Brady Bunch Variations for Piano and Orchestra", with the Orchestre national d'Île-de-France at the Théâtre du Châtelet in Paris.
Later that decade, Carnegie Hall awarded Mehldau another commission – to write the song cycle Love Songs for singer Anne Sofie von Otter; they premiered it together in 2009 and recorded the songs the following year.
In 2009 Mehldau began a two-year period as curator of London's Wigmore Hall jazz series, which included a performance with von Otter in the second year.

In 2009 Mehldau also recorded Highway Rider, an album that combined his usual trio with guest musicians and a 28-piece orchestra.
Again based compositionally on the theme of travel or a journey, the album was produced by Brion, and, in critic Mike Hobart's description, "probes the confluence of the arbitrary and non-arbitrary in music, of balancing what is committed to the page with improvisation."
This was pursued further in the winter of 2010–11, in public performances of pieces from the album in the US and Europe.
Mehldau's trio returned to the studio for the first time in several years in 2008 and again in 2011, resulting in Ode, an album of the pianist's originals, and Where Do You Start, an album of covers.
Down Beat reviewer Jim Macnie commented that, on the former album, "More than ever, Mehldau uses his instrument as a drum, popping staccato notes into the maw of the rhythm section's formidable bustle."

During 2010–11 Mehldau held Carnegie Hall's Richard and Barbara Debs Composer's Chair, the first jazz musician to do so.
He also played and recorded piano duets with Kevin Hays.
This collaboration was on arrangements by Patrick Zimmerli, with whom Mehldau had attended high school.
One piece from their album, Modern Music, featured the pianists playing a composed left-hand part while improvising with the other hand; "to do both at once is a real test.
The brain feels like it's split in half", commented Mehldau.
Also in 2011 Mehldau toured with von Otter again, had piano–mandolin duets with Chris Thile, and played a series of duet concerts with Redman in Europe, six pieces from
In 2005 Ballard replaced Rossy as the drummer in Mehldau's trio. This, in the view of critic Ray Comiskey, did not radically change the trio's sound, but it did give them "a harder edge and pushed Mehldau more, with bassist Larry Grenadier left more in a fulcrum role, the centre around which piano and drums cavort." Another critic, Ben Ratliff, suggested that the new trio's sound was "denser and more tumultuous", with rhythms more overt than with the previous trio. In February 2005 Mehldau performed in Hong Kong for the first time, with his new trio. Their first album, Day Is Done, was recorded the following month.
Mehldau continued to expand beyond trio and solo playing. In the spring of 2005 he premiered a song cycle that he had written for classical music singer Renée Fleming. This association was based on a commission from Carnegie Hall; their 2006 recording contained music set to poems by Rainer Maria Rilke and Louise Bogan. Mehldau also collaborated with guitarist Pat Metheny from 2005 – they recorded two albums together that year, along with Grenadier and Ballard, and in 2007 went on a worldwide tour.
Another Village Vanguard recording, Brad Mehldau Trio Live, was recorded in 2006 and released two years later. This also contained a variety of sources of material, including "Wonderwall" by rock band Oasis, "Black Hole Sun" by grunge band Soundgarden, and Chico Buarque's samba "O Que Será"; "it's business as usual – state-of-the-art contemporary jazz piano", commented Fordham. A further recording from 2006 was released as Live in Marciac in 2011; this contained two CDs and one DVD of a solo concert by the pianist. Mehldau asserted that his third solo recording "is the beginning of a freer approach, [...] and maybe [contains] more ease and fluidity in a musical texture with several simultaneous voices". In 2006 Mehldau also played on saxophonist Michael Brecker's final album, Pilgrimage.
In March 2007 Mehldau first performed his piano concerto "The Brady Bunch Variations for Piano and Orchestra", with the Orchestre national d'Île-de-France at the Théâtre du Châtelet in Paris. Later that decade, Carnegie Hall awarded Mehldau another commission – to write the song cycle Love Songs for singer Anne Sofie von Otter; they premiered it together in 2009 and recorded the songs the following year. In 2009 Mehldau began a two-year period as curator of London's Wigmore Hall jazz series, which included a performance with von Otter in the second year.
In 2009 Mehldau also recorded Highway Rider, an album that combined his usual trio with guest musicians and a 28-piece orchestra. Again based compositionally on the theme of travel or a journey, the album was produced by Brion, and, in critic Mike Hobart's description, "probes the confluence of the arbitrary and non-arbitrary in music, of balancing what is committed to the page with improvisation." This was pursued further in the winter of 2010–11, in public performances of pieces from the album in the US and Europe. Mehldau's trio returned to the studio for the first time in several years in 2008 and again in 2011, resulting in Ode, an album of the pianist's originals, and Where Do You Start, an album of covers. Down Beat reviewer Jim Macnie commented that, on the former album, "More than ever, Mehldau uses his instrument as a drum, popping staccato notes into the maw of the rhythm section's formidable bustle."
During 2010–11 Mehldau held Carnegie Hall's Richard and Barbara Debs Composer's Chair, the first jazz musician to do so. He also played and recorded piano duets with Kevin Hays. This collaboration was on arrangements by Patrick Zimmerli, with whom Mehldau had attended high school. One piece from their album, Modern Music, featured the pianists playing a composed left-hand part while improvising with the other hand; "to do both at once is a real test. The brain feels like it's split in half", commented Mehldau. Also in 2011 Mehldau toured with von Otter again, had piano–mandolin duets with Chris Thile, and played a series of duet concerts with Redman in Europe, six pieces from
Brad Mehldau