diff --git a/src/canvas.rs b/src/canvas.rs
index 7678287..4aed98f 100644
--- a/src/canvas.rs
+++ b/src/canvas.rs
@@ -43,6 +43,7 @@ impl Canvas {
                     objects: HashMap::new(),
                     name: name.to_string(),
                     _render_cache: None,
+                    hidden: false,
                 })
                 .collect(),
             ..Self::default_settings()
@@ -233,6 +234,7 @@ impl Canvas {
             name: name.to_string(),
             objects,
             _render_cache: None,
+            hidden: false,
         }
     }
 
@@ -267,6 +269,7 @@ impl Canvas {
             name: layer_name.to_owned(),
             objects,
             _render_cache: None,
+            hidden: false,
         }
     }
 
@@ -512,7 +515,7 @@ impl Canvas {
         )
     }
 
-    pub fn render(&mut self, layers: &Vec<&str>, render_background: bool) -> Result<String> {
+    pub fn render(&mut self, render_background: bool) -> Result<String> {
         let background_color = self.background.unwrap_or_default();
         let mut svg = svg::Document::new();
         if render_background {
@@ -525,12 +528,7 @@ impl Canvas {
                     .set("fill", background_color.render(&self.colormap)),
             );
         }
-        for layer in self
-            .layers
-            .iter_mut()
-            .filter(|layer| layers.contains(&"*") || layers.contains(&layer.name.as_str()))
-            .rev()
-        {
+        for layer in self.layers.iter_mut().filter(|layer| !layer.hidden).rev() {
             svg = svg.add(layer.render(self.colormap.clone(), self.cell_size, layer.object_sizes));
         }
 
diff --git a/src/layer.rs b/src/layer.rs
index a41e17b..e303a50 100644
--- a/src/layer.rs
+++ b/src/layer.rs
@@ -1,4 +1,4 @@
-use crate::{ColorMapping, ColoredObject, Fill, Filter, ObjectSizes, Region};
+use crate::{ColorMapping, ColoredObject, Fill, Filter, ObjectSizes, Region, Toggleable};
 use std::{collections::HashMap, fmt::Display};
 
 #[derive(Debug, Clone, Default)]
@@ -7,6 +7,7 @@ pub struct Layer {
     pub object_sizes: ObjectSizes,
     pub objects: HashMap<String, ColoredObject>,
     pub name: String,
+    pub hidden: bool,
     pub _render_cache: Option<svg::node::element::Group>,
 }
 
@@ -17,9 +18,22 @@ impl Layer {
             objects: HashMap::new(),
             name: name.to_string(),
             _render_cache: None,
+            hidden: false,
         }
     }
 
+    pub fn hide(&mut self) {
+        self.hidden = true;
+    }
+
+    pub fn show(&mut self) {
+        self.hidden = false;
+    }
+
+    pub fn toggle(&mut self) {
+        self.hidden.toggle();
+    }
+
     pub fn object(&mut self, name: &str) -> &mut ColoredObject {
         self.objects.get_mut(name).unwrap()
     }
diff --git a/src/lib.rs b/src/lib.rs
index 58854f4..d1ed0f5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -190,5 +190,15 @@ impl<'a, C> Context<'a, C> {
     }
 }
 
+trait Toggleable {
+    fn toggle(&mut self);
+}
+
+impl Toggleable for bool {
+    fn toggle(&mut self) {
+        *self = !*self;
+    }
+}
+
 #[allow(unused)]
 fn main() {}
diff --git a/src/main.rs b/src/main.rs
index 4e6fadc..b1826be 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,7 +13,7 @@ pub fn run(args: cli::Args) -> Result<()> {
 
     if args.cmd_image && !args.cmd_video {
         canvas = examples::dna_analysis_machine();
-        let rendered = canvas.render(&vec!["*"], true)?;
+        let rendered = canvas.render(true)?;
         if args.arg_file.ends_with(".svg") {
             std::fs::write(args.arg_file, rendered).unwrap();
         } else {
diff --git a/src/objects.rs b/src/objects.rs
index 8c94565..0c4cdb1 100644
--- a/src/objects.rs
+++ b/src/objects.rs
@@ -62,11 +62,15 @@ impl ColoredObject {
         colormap: &ColorMapping,
         id: &str,
     ) -> svg::node::element::Group {
-        let group = self.object.render(cell_size, object_sizes, id);
+        let mut group = self.object.render(cell_size, object_sizes, id);
 
-        let rendered_transforms = self
+        match self
             .transformations
-            .render_attribute(colormap, !self.object.fillable());
+            .render_attribute(colormap, !self.object.fillable())
+        {
+            (key, _) if key.is_empty() => (),
+            (key, value) => group = group.set(key, value),
+        }
 
         let mut css = String::new();
         if !matches!(self.object, Object::RawSVG(..)) {
@@ -81,9 +85,7 @@ impl ColoredObject {
             .join(" ")
             .as_ref();
 
-        group
-            .set("style", css)
-            .set(rendered_transforms.0, rendered_transforms.1)
+        group.set("style", css)
     }
 }
 
@@ -177,9 +179,8 @@ impl<T: RenderAttribute> RenderAttribute for Vec<T> {
     fn render_fill_attribute(&self, colormap: &ColorMapping) -> (String, String) {
         (
             self.first()
-                .unwrap()
-                .render_fill_attribute(colormap)
-                .0
+                .map(|v| v.render_fill_attribute(colormap).0)
+                .unwrap_or_default()
                 .clone(),
             self.iter()
                 .map(|v| v.render_fill_attribute(colormap).1.clone())
@@ -190,9 +191,8 @@ impl<T: RenderAttribute> RenderAttribute for Vec<T> {
     fn render_stroke_attribute(&self, colormap: &ColorMapping) -> (String, String) {
         (
             self.first()
-                .unwrap()
-                .render_stroke_attribute(colormap)
-                .0
+                .map(|v| v.render_stroke_attribute(colormap).0)
+                .unwrap_or_default()
                 .clone(),
             self.iter()
                 .map(|v| v.render_stroke_attribute(colormap).1.clone())
diff --git a/src/video.rs b/src/video.rs
index 6dcaa50..3eabd2c 100644
--- a/src/video.rs
+++ b/src/video.rs
@@ -18,7 +18,8 @@ use crate::{
     preview,
     sync::SyncData,
     ui::{self, setup_progress_bar, Log as _},
-    Canvas, ColoredObject, Context, MidiSynchronizer, MusicalDurationUnit, Syncable,
+    Canvas, ColoredObject, Context, LayerAnimationUpdateFunction, MidiSynchronizer,
+    MusicalDurationUnit, Syncable,
 };
 
 pub type BeatNumber = usize;
@@ -449,6 +450,23 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
         Self { commands, ..self }
     }
 
+    pub fn bind_amplitude(
+        self,
+        layer: &'static str,
+        stem: &'static str,
+        update: &'static LayerAnimationUpdateFunction,
+    ) -> Self {
+        self.with_hook(Hook {
+            when: Box::new(move |_, _, _, _| true),
+            render_function: Box::new(move |canvas, context| {
+                let amplitude = context.stem(stem).amplitude_relative();
+                update(amplitude, canvas.layer(layer), context.ms)?;
+                canvas.layer(layer).flush();
+                Ok(())
+            }),
+        })
+    }
+
     pub fn total_frames(&self) -> usize {
         self.fps * (self.duration_ms() + self.start_rendering_at) / 1000
     }
@@ -470,7 +488,7 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
         let mut rendered_frames: HashMap<usize, String> = HashMap::new();
         let progress_bar = self.setup_progress_bar();
 
-        for (frame, _, ms) in self.render_frames(&progress_bar, vec!["*"], true)? {
+        for (frame, _, ms) in self.render_frames(&progress_bar, true)? {
             rendered_frames.insert(ms, frame);
         }
 
@@ -493,7 +511,7 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
         workers_count: usize,
         preview_only: bool,
     ) -> Result<()> {
-        self.render_composition(output_file, vec!["*"], true, workers_count, preview_only)
+        self.render(output_file, true, workers_count, preview_only)
     }
 
     pub fn render_layers_in(&self, output_directory: String, workers_count: usize) -> Result<()> {
@@ -503,9 +521,8 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
             .iter()
             .map(|l| vec![l.name.as_str()])
         {
-            self.render_composition(
+            self.render(
                 format!("{}/{}.mov", output_directory, composition.join("+")),
-                composition,
                 false,
                 workers_count,
                 false,
@@ -518,7 +535,6 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
     pub fn render_frames(
         &self,
         progress_bar: &ProgressBar,
-        composition: Vec<&str>,
         render_background: bool,
     ) -> Result<Vec<(String, usize, usize)>> {
         let mut context = Context {
@@ -611,7 +627,7 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
             }
 
             if context.frame != previous_rendered_frame {
-                let rendered = canvas.render(&composition, render_background)?;
+                let rendered = canvas.render(render_background)?;
 
                 previous_rendered_beat = context.beat;
                 previous_rendered_frame = context.frame;
@@ -627,10 +643,9 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
         ui::setup_progress_bar(self.total_frames() as u64, "Rendering")
     }
 
-    pub fn render_composition(
+    pub fn render(
         &self,
         output_file: String,
-        composition: Vec<&str>,
         render_background: bool,
         workers_count: usize,
         _preview_only: bool,
@@ -651,9 +666,7 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
         self.progress_bar.set_prefix("Rendering");
         self.progress_bar.set_message("");
 
-        for (frame, no, ms) in
-            self.render_frames(&self.progress_bar, composition, render_background)?
-        {
+        for (frame, no, ms) in self.render_frames(&self.progress_bar, render_background)? {
             frames_to_write.push((frame, no, ms));
         }
 
@@ -697,7 +710,8 @@ impl<AdditionalContext: Default> Video<AdditionalContext> {
                                 frames_output_directory,
                                 aspect_ratio,
                                 resolution,
-                            ).unwrap();
+                            )
+                            .unwrap();
                             progress_bar.inc(1);
                         }
                     })
diff --git a/src/web.rs b/src/web.rs
index 86ed0e2..56c4cff 100644
--- a/src/web.rs
+++ b/src/web.rs
@@ -65,13 +65,13 @@ pub fn map_to_midi_controller() {}
 
 #[wasm_bindgen]
 pub fn render_canvas_into(selector: String) -> () {
-    let svgstring = canvas().render(&vec!["*"], false).unwrap_throw();
+    let svgstring = canvas().render(false).unwrap_throw();
     append_new_div_inside(svgstring, selector)
 }
 
 #[wasm_bindgen]
 pub fn render_canvas_at(selector: String) -> () {
-    let svgstring = canvas().render(&vec!["*"], false).unwrap_throw();
+    let svgstring = canvas().render(false).unwrap_throw();
     replace_content_with(svgstring, selector)
 }
 
@@ -135,15 +135,9 @@ impl From<(MidiEvent, MidiEventData)> for MidiMessage {
 }
 
 #[wasm_bindgen]
-pub fn render_canvas(layers_pattern: Option<String>, render_background: Option<bool>) -> () {
+pub fn render_canvas(render_background: Option<bool>) -> () {
     canvas()
-        .render(
-            &match layers_pattern {
-                Some(ref pattern) => vec![pattern],
-                None => vec!["*"],
-            },
-            render_background.unwrap_or(false),
-        )
+        .render(render_background.unwrap_or(false))
         .unwrap_throw();
 }
 
@@ -214,7 +208,7 @@ pub struct LayerWeb {
 #[wasm_bindgen]
 impl LayerWeb {
     pub fn render(&self) -> String {
-        canvas().render(&vec![&self.name], false).unwrap_throw()
+        canvas().render(false).unwrap_throw()
     }
 
     pub fn render_into(&self, selector: String) -> () {