Developer Harmonix has announced a slew of new features coming to Rock Band 4 through future updates this year. Speaking at a PAX East panel, titled "Rock Band: Present, Past and Future", the developer revealed that an online multiplayer mode is finally coming this winter in addition to the music-based game's first expansion pack releasing in the fall.

Fans have been calling for synchronous online multiplayer since the popular game's release in October 2015. At the time, project manager Daniel Sussman said there are multiple technical hurdles to overcome before such a feature could be delivered. The feature is slated for release this holiday season.

"Synchronous online multiplayer will be like Quickplay, modified to provide a fair and streamlined experience for console friends looking to play Rock Band 4 together online," Harmonix community manager Criss Burki said in a PlayStation Blog post. "We'll be implementing enhancements on the back end to address issues for folks who don't have the same DLC libraries and want a more fluid process for choosing songs together as a band (you all know that one person who would pick a song before you had the chance)."

Harmonix also announced that the title will be getting its first paid expansion pack this fall including music library improvements, the ability to filter by genre and rate songs and some more features that the developer will further elaborate during E3. According to community lead Josh Harrison, the upcoming expansion pack is inspired by those for games such as World of Warcraft and destiny. He further described the features as "really huge and brand new".

An adapter will also be released for the Xbox One version of Rock Band 4 alongside the expansion pack which will allow the Ion drums to work. Ion drums are already supported in the title's PlayStation 4 version.

In May, the developer is teaming up with Gearbox Software to bring to bring two characters from first-person shooter Battleborn – Thorn and Miko to Rock Band 4 as playable band members. This isn't the title's first crossover. In 2015, Harmonix and Bethesda came together to bring Fallout's Vault 111 as a free character costume to the game. However, this is the first time that actual characters are making appearances in the series. A double kick feature will be coming out in May as well.

Another top-requested item from fans, practice mode, will be released in June. The welcome feature will allow users to play through sections of a song that they need extra help with.

There will be no updates during the summer for Rock Band 4, marking "the end of chapter 1", according to the panel. The development team says the break will allow them to polish up its massive upcoming update in the fall.

While fans anxiously await the game's host of updates, Harmonix confirmed the DLC tracks coming to Rock Band 4 this week which include What I Like About You by The Romantics, Redneck by Lamb of God and Dope Nose by Weezer. Harrison added that fans will be happy with the DLC songs coming in May, but did not share any further details.