We need some good graphics for the main sampler screen. This is where you can do rudimentary editing of the samples that are played in the sequencer.
There are two screens. The main screen with the controls:

• Volume (this one may be changed later)
• Speed (Playspeed. The sample also pitches up or down)
• Filter (in the middle the sound is unchanged, away from center it engages either hi-pass or lo-pass filters)
• Sample select (already implemented)

This is what we have so far:

The task is quite simple:

• Fit in the remaining three controls on the main screen. (Volume (blue), speed (green), filter (yellow))

Feel free to play around with some graphical representations of filter and speed, etc.