How to improve design of voice matching game application

I am looking into producing a special kind of input device for applications such as a computer or television screen game, which I would like to call VoiceMatch.

Description of device:
The hardware device consists of a hardware mixer midi-device-like small keyboard with a knob followed by three vertical sliders on each side, so that four controls correspond to each hand. This is for the one player mode.
In the two player mode each player uses a single set of controls against the other. The knob in the game works as an emotion control knob and ha stops for different emotions such as anger, joy drive, swiftness, vigor, strength, and so on, corresponding to the singer the player manipulates.

The singer sings continuously as the user operates the knobs and the sliders. The sliders are used to make a composite voice for the singer, made of three primary voices of three other singers that the player can hear before the match.
The three primary singers all have their own voice characteristics, but the composite singer can acquire these characteristics, overriding their own, "natural", "feeble", characteristics. The amount of slider uppushing determines how much the primary characteristics corresponding to the slider's primary singer override the feeble, natural, composite voice acquired by the singer, with respect to the emotion selected by the singer's emotion knob.

In a game there are two singers facing each other, which sing continuously or take turns. Each player gains points according to how well the player can get the composite song to turn out well with respect to the two player-singers selected progressively by the computer for each match by the two gamer players.

Question:
How can I improve the user experience for this software and especially for the hardware interface underlying it?

Thanks.