Carpenter has been both criticized by some and praised by others for his unorthodox interpretations of the standard organ repertoire. Registrations rarely follow those suggested by the composer, and Carpenter often takes dramatic liberties in articulation. Carpenter is also noted for his advocacy of the digital organ, particularly development of a touring electronic organ, citing factors such as the obstacles the pipe organ imposes on the ability of a traveling performer to enjoy an ongoing relationship with a single instrument in the same manner as many other instrumentalists. Despite this, he frequently performs on pipe organs, often garnering major exposure for the instrument. He designed and commissioned the
International Touring Organ (ITO), Opus 8 of the
Marshall and Ogletree company, a one-of-a-kind, customized, "full-scale portable organ sonically tailorable to any acoustic environment", which took ten years and cost $2 million to build. Since its premiere in March 2014, he no longer has to learn a new instrument for every performance which he characterized as maddening, and he now tours worldwide to venues that have never had an organ. The story of the ITO is the subject of the 2015 documentary "The Sound of My Life". On March 18, 2014, Carpenter, arriving at
Birmingham Airport for a performance at
Birmingham Symphony Hall the following day, was refused permission to enter the
United Kingdom by the British
Border Force which applied immigration rules for visiting foreign artists. He returned to Britain the following day, and after a short detention at the airport, performed a reduced version of his planned recital. The
House of Lords initiated an inquiry with the
Home Office which determined that Carpenter lacked the required sponsor's certificate and that no mistreatment occurred, though it conceded that "Although the guidelines and policies were correctly followed by officers, Border Force accepts that more could have been done to assist Mr Carpenter." ==Personal life==