The rebrand extends the 4Music brand, which currently transmits during slots on terrestrial Channel 4, into digital TV. Content will include exclusive live events, original series and a range of new and classic music videos.
The rebrand has been timed to coincide with live coverage of the V Festival, which takes place from August 16-17, and will feature headline performances by Muse and The Verve.
David Young, Box TV's programming director, said: "This is the first major initiative since we formed this incredibly exciting joint venture.
"We already have the number one music channel in the UK and now we're going to take all the best bits of our music video content and combine them with a refined schedule of quality long-form music and music-based entertainment programming."
The V Festival programming will be followed by coverage of Bestival, where Amy Winehouse will headline; and Orange RockCorps, a music-volunteering programme backed by Orange, Sony Ericsson and Channel 4 that will climax with a concert at The Royal Albert Hall.
The channel will also transmit shows including 'Live from Abbey Road', '4Music Presents', 'T-Mobile Transmission' and 'Ibiza Rocks with Sony Ericsson'. Bands and performers will also make appearances on programmes including 'The Sunday Night Project'.
Gidon Katz, Box TV's managing director, said: "4Music merges the best terrestrial content with multi-channel scheduling to offer advertisers, production companies and record labels a unique opportunity to connect with the 16-34-year-old audience."
Viewers familiar with presenters from T4 and 4Music will recognise many of the faces appearing on the channel, including Alexa Chung, Nick Grimshaw, Miquita Oliver and Steve Jones.
The Hits currently attracts an average audience of 10.5m viewers per month, 4m of whom are aged between 16 and 34 years.
It will rebrand as 4Music on August 15 and will be available to watch on Sky channel 360, Virgin channel 330 and Freeview channel 18.