What Nine Inch Nails album fell sharply in the April 2008 charts?

The Nine Inch Nails album was Ghosts I–IV.

Ghosts I–IV is a 36-track instrumental album released by Nine Inch Nails in 2008. Trent Reznor initially made it available online on March 2, using a flexible, direct-to-fans model that included a free download and several paid editions. A physical edition followed in April, bringing the project into conventional album charts.

The album debuted at number 14 on the US Billboard 200 after its physical release, selling about 26,000 copies in its first week. Its chart performance was unusual because much of the album had already circulated digitally, while the retail edition arrived later. In the United Kingdom, it entered the albums chart at number 60 on April 19, 2008.

Unlike most Nine Inch Nails records, Ghosts I–IV contains no conventional lead vocals or standard pop-song structure. It is a collection of atmospheric instrumental pieces, divided into four sections. The album also foreshadowed Reznor's later film-scoring work with Atticus Ross.