How Rock Band 4’s new solo feature works — and how Harmonix made it happen

A new twist in Rock Band’s gameplay will likely throw even the most familiar players for a loop, and the way it works is like magic.

At first glance, Harmonix’s return to consoles with Rock Band 4 looks and sounds mostly similar to its predecessors. Note prompts rain down from the top of the screen while players do their best to keep up on guitar and drum controllers to some of rock music’s most popular tunes. Series fans will feel right at home — at least at first.

The Rock Band 4 solo feature gives you an opportunity to take a break from precision note matching for a bit of self-expression. The cascading markers that correspond to specific buttons or drums are replaced with new patterns that are suggestions for the various input devices, though you can disregard these. You can use any of the controls at any time during these segments, each with their own unique musical result. For example, strumming while holding one button might trigger a choked series of guitar notes. And holding down all of the buttons while strumming often plays harmonics. The idea is to have players exploring the game’s controllers to create their own music.

Harmonix put a lot of work into the illusion of having each control trigger sound like its own instance of a solo lick. A combination of musical chops and technical implementation has every strum, press, or hit sounding like it was always part of the song, never falling out of harmony or breaking the stylistic framework of the original song. It works incredibly well, and it feels like you’re playing your own solo. The best part is that you don’t have to know anything about music to sound pretty good.

GamesBeat spoke with Harmonix’s Greg LoPiccolo, the creative lead on Rock Band 4, on how the solo feature came to be as well as what went into making it work.

GamesBeat: How did this solo feature come about? Was it something that you’ve wanted to put in before but couldn’t?

Greg LoPiccolo: We have wanted to do this feature going all the way back to our work on the original Guitar Hero back in 2004 and 2005, but it took us a long time to work through the design and technical issues that we needed to solve to make it good as we needed it to be. A few months before Rock Band 4 preproduction even started, Alex Rigopulos came to me and Eric [Brosius, RB4 audio lead] and said, essentially, now’s your chance to make this happen. So we spent an entire summer on the prototype, which came out well enough to convince us that it should be a big part of Rock Band 4.

GamesBeat: Were there any technical challenges in putting this in? And how did the current generation of consoles help?

LoPiccolo: A lot of the challenge was in the design domain; just figuring how to present meaningful choices to the player in an intuitive way. We had a few technical hurdles as well.

One big issue was getting the tone to sound like an actual electric guitar played through an amplifier.  We got a big assist from a set of sophisticated BIAS guitar amp models that we have licensed from Positive Grid. They go a long way toward creating the illusion of overdriven electric guitar. Another challenge was creating the illusion that players are playing in time, given that most modern AV setups have tons of lag. You can’t assume that the system will respond to the player’s input quickly enough to be musically satisfying, so there are a set of technical and design features to get around this system limitation.

GamesBeat: How much manpower did you have to put into making sure each song has the full set of solo options?

LoPiccolo: Quite a bit, actually! When we got hooked on the feature internally, we realized that players — including ourselves — were going to want to play solos on all the appropriate songs, and we’re actually working through what that means now.

GamesBeat: I’d imagine that someone had to musically break down each song to make sure that these phrases not only harmonize but also fit together and complement the style. 

LoPiccolo: We have put a lot of work in behind the scenes to make sure the system does a pretty great job of making the solos work. At some point, it ends up being up to the taste and judgment of the player to make good choices – which is why we are so excited about the system as a whole – players have a lot of control over the solos that they play.

GamesBeat: And you had to do this for every song? Does that limit this feature to only certain songs in the library? 

LoPiccolo: We think this is a gameplay breakthrough, so we are pretty motivated to support in as many play situations where it makes sense.

GamesBeat: How much of this feature was driven by the desire to use those high frets?

LoPiccolo: It was actually the other way around – once we got well into development of the feature, we realized how much the high frets could improve it.  But it feels great to finally have them integrated into gameplay in a meaningful way – they are really earning their keep in Rock Band 4.

GamesBeat: Are there any other features that we can expect that will open up or expand upon the classic Rock Band gameplay?

LoPiccolo: Freestyle Vocals let experienced singers “color outside the lines,” and improvise melodies and harmonies while still getting scored.  Our new “Play a Show” mode works as the ultimate party experience, and keeps the band onstage without having to go back to the song library for new choices.  Band members can vote on what songs to play, swap parts and change difficulty, and carry their streak multipliers and overdrive energy between songs.  There are a host of big and small tweaks to augment every mode – it really feels like the Rock Band we have always wanted to make.