             format: "%0.3f s",
             value: osc.attackDuration, maximum: 2,
             color: AKColor.green
-        ) { duration in
-            osc.attackDuration = duration
+        ) { sliderValue in
+            osc.attackDuration = sliderValue
         })
 
         addSubview(AKPropertySlider(

            property: "OSC Morph Index",
            value: osc.index, minimum: 0, maximum: 3,
            color: AKColor.green
        ) { index in
            osc.index = index
        })

        addSubview(AKPropertySlider(

            format: "%0.3f",
            value: generatorBooster.gain, minimum: 0, maximum:4,
            color: AKColor.green
        ) { sliderValue in
            generatorBooster.gain = sliderValue
        })

        addSubview(AKPropertySlider(
            property: "FILTER Frequency Cutoff",
            value: filter.cutoffFrequency, minimum: 1, maximum: 12_000,
            color: AKColor.red
        ) { sliderValue in
            filter.cutoffFrequency = sliderValue
        })

        addSubview(AKPropertySlider(
            property: "FILTER Frequency Resonance",
            value: filter.resonance, minimum: 0, maximum: 4,
            color: AKColor.red
        ) { sliderValue in
            filter.resonance = sliderValue
        })

        addSubview(AKPropertySlider(
