diff --git a/src/main.py b/src/main.py
index 990dea1..7048379 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,18 +1,33 @@
+print("=== TerminalDAW - Version 0.0.1 ===\n")
+
 from ui.app import AppUI
 from project import Project, ProjectChannel, AudioChannelChunk
 import librosa
+import sounddevice
+import mp3
 
 
 if __name__ == "__main__":
     print("Loading project...")
-    """test_project = Project(channels=[
-        ProjectChannel(chunks=[
-            AudioChannelChunk(*librosa.load("120 bpm amen break.mp3", mono=False), position=0, name="120 bpm amen break.mp3"),
-        ], name="drums"),
-    ])
-    #test_project.write_to_file("test_project.tdp")"""
-    test_project = Project.from_file("test_project.tdp")
+    """test_project = Project(song_length=2)
     
+    drum_channel = ProjectChannel(
+        test_project,
+        name="Drums",
+        volume=5,
+        
+    )
+    drum_channel.chunks.append(AudioChannelChunk(
+        drum_channel,
+        position=0,
+        *librosa.load("120 bpm amen break.mp3", mono=False, sr=test_project.sample_rate),
+        name="120 bpm amen break.mp3"
+    ))
+
+    test_project.channels.append(drum_channel)
+    
+    test_project.write_to_file("test_project.tdp")"""
+    test_project = Project.from_file("test_project.tdp")
     
     # start the ui
     print("Starting UI...")
diff --git a/src/output.mp3 b/src/output.mp3
new file mode 100644
index 0000000..e69de29
diff --git a/src/project.py b/src/project.py
index c8d7440..ec5b458 100644
--- a/src/project.py
+++ b/src/project.py
@@ -2,6 +2,7 @@ import msgpack
 import enum
 import numpy as np
 import msgpack_numpy
+import pedalboard
 from dataclasses import dataclass, asdict
 
 
@@ -18,13 +19,18 @@ class ChunkType(enum.Enum):
     MIDI = enum.auto()
 
 class ChannelChunk:
-    def __init__(self, position: float = 0.0, name: str = "Chunk", chunk_type: ChunkType = ChunkType.CHUNK):
+    def __init__(self, channel, position: float = 0.0, name: str = "Chunk", chunk_type: ChunkType = ChunkType.CHUNK):
+        self.channel = channel
         self.position = position # position is how many bars into the song the chunk is
         self.name = name
         self.chunk_type = chunk_type
         
-    def from_json(json: dict) -> ChannelChunk:
+    def render(self):
+        pass
+        
+    def from_json(json: dict, channel) -> ChannelChunk:
         return ChannelChunk(
+            channel,
             chunk_type = ChunkType(json["type"]),
             name = json["name"],
             position = json["position"]
@@ -38,13 +44,27 @@ class ChannelChunk:
         }
 
 class AudioChannelChunk(ChannelChunk):
-    def __init__(self, audio_data: np.ndarray, sample_rate: int, position: float = 0.0, name: str = "Sample"):
-        super().__init__(position, name, chunk_type=ChunkType.AUDIO)
+    def __init__(self, channel, audio_data: np.ndarray, sample_rate: int, position: float = 0.0, name: str = "Sample"):
+        super().__init__(channel, position, name, chunk_type=ChunkType.AUDIO)
         self.audio_data = audio_data
         self.sample_rate = sample_rate
         
-    def from_json(json: dict) -> ChannelChunk:
+    def render(self):
+        start_sample = int(self.position * self.channel.project.samples_per_bar)
+        
+        audio = self.audio_data.T
+        
+        # ensure stereo
+        if audio.ndim == 1:
+            audio = np.stack([audio, audio], axis=1)
+            
+        end_sample = start_sample + len(audio)
+
+        return start_sample, end_sample, audio
+        
+    def from_json(json: dict, channel) -> ChannelChunk:
         return AudioChannelChunk(
+            channel,
             name = json["name"],
             position = json["position"],
             audio_data = json["audio_data"],
@@ -66,7 +86,8 @@ chunk_type_associations = {
 }
 
 class ProjectChannel:
-    def __init__(self, name: str = "", volume: int = 0, pan: int = 0, mute: bool = False, solo: bool = False, chunks: list[ChannelChunk] = []):
+    def __init__(self, project, name: str = "", volume: int = 0, pan: int = 0, mute: bool = False, solo: bool = False, chunks: list[ChannelChunk] = []):
+        self.project = project
         self.name = name
         self.volume = volume
         self.pan = pan
@@ -74,16 +95,57 @@ class ProjectChannel:
         self.solo = solo
         self.chunks = chunks
         
-    def from_json(json: dict) -> ProjectChannel:
-        return ProjectChannel(
+        self.board = pedalboard.Pedalboard([
+            pedalboard.Reverb()
+        ])
+        
+    def pan_stereo(self, stereo, pan):
+        pan = np.clip(pan, -1.0, 1.0)
+
+        left_gain = np.cos((pan + 1) * np.pi / 4)
+        right_gain = np.sin((pan + 1) * np.pi / 4)
+
+        out = stereo.copy()
+        out[:, 0] *= left_gain
+        out[:, 1] *= right_gain
+
+        return out
+        
+    def render(self):
+        buffer = np.zeros((self.project.total_song_samples, 2), dtype=np.float32)
+        
+        # render each chunk
+        for chunk in self.chunks:
+            start, end, audio = chunk.render()
+            buffer[start:end] += audio
+            
+        # apply effects
+        buffer = self.board(buffer, self.project.sample_rate)
+            
+        # apply volume
+        gain = 10 ** (self.volume / 20)
+        buffer *= gain
+        
+        # pan
+        self.pan_stereo(buffer, self.pan/100)
+        
+        return buffer
+        
+    def from_json(json: dict, project) -> ProjectChannel:
+        channel = ProjectChannel(
+            project,
             name = json["name"],
             volume = json["volume"],
             pan = json["pan"],
             mute = json["mute"],
             solo = json["solo"],
-            chunks = [chunk_type_associations[ChunkType(chunk["type"])].from_json(chunk) for chunk in json["chunks"]]
+            
         )
         
+        channel.chunks = [chunk_type_associations[ChunkType(chunk["type"])].from_json(chunk, channel) for chunk in json["chunks"]]
+        
+        return channel
+        
     def to_json(self):
         return {
             "name": self.name,
@@ -95,30 +157,51 @@ class ProjectChannel:
         }
 
 class Project:
-    def __init__(self, channels: list[ProjectChannel], version: float = 1.0, bpm: float = 120, time_signature: TimeSignature = TimeSignature(4, 4)):
+    def __init__(self, channels: list[ProjectChannel] = [], version: float = 1.0, bpm: float = 120, time_signature: TimeSignature = TimeSignature(4, 4), song_length: float = 16, sample_rate: int = 44100):
         self.version = version
         self.bpm = bpm
+        self.sample_rate = sample_rate
         self.time_signature = time_signature
         self.channels = channels
+        self.song_length = song_length # length of the song in bars
+        
+        self.seconds_per_bar = (60.0 / self.bpm) * self.time_signature.beats_per_measure
+        self.samples_per_bar = int(self.seconds_per_bar * self.sample_rate)
+        self.total_song_samples = int(self.samples_per_bar * self.song_length)
+        
+    def render(self):
+        buffer = np.zeros((self.total_song_samples, 2), dtype=np.float32)
+        
+        for channel in self.channels:
+            buffer += channel.render()
+        
+        return buffer
         
     def from_file(file_path: str) -> Project:
         with open(file_path, "rb") as f:
             return Project.from_json(msgpack.unpackb(f.read()))
             
     def from_json(json: dict) -> Project:
-        return Project(
+        project = Project(
             version = json["version"],
             time_signature = TimeSignature(json["time_signature"]["beats_per_measure"], json["time_signature"]["note_value"]),
             bpm = json["bpm"],
-            channels = [ProjectChannel.from_json(channel) for channel in json["channels"]]
+            song_length = json["song_length"],
+            sample_rate = json["sample_rate"]
         )
         
+        project.channels = [ProjectChannel.from_json(channel, project) for channel in json["channels"]]
+        
+        return project
+        
     def to_json(self):
         return {
             "version": self.version,
             "time_signature": asdict(self.time_signature),
             "bpm": self.bpm,
-            "channels": [channel.to_json() for channel in self.channels]
+            "channels": [channel.to_json() for channel in self.channels],
+            "song_length": self.song_length,
+            "sample_rate": self.sample_rate
         }
         
     def write_to_file(self, file_path: str):
diff --git a/src/song_player.py b/src/song_player.py
deleted file mode 100644
index 43b0cb8..0000000
--- a/src/song_player.py
+++ /dev/null
@@ -1,13 +0,0 @@
-from project import Project
-import pedalboard
-import sounddevice as sd
-import numpy as np
-from textual.app import App
-
-
-class SongPlayer:
-    def __init__(self, app: App):
-        self.app = app
-    
-    def play_song(self, project: Project):
-        pass
\ No newline at end of file
diff --git a/src/test_project.tdp b/src/test_project.tdp
index 4bed220..f311e32 100644
Binary files a/src/test_project.tdp and b/src/test_project.tdp differ
diff --git a/src/ui/app.py b/src/ui/app.py
index 96fa5d6..ae7e7d5 100644
--- a/src/ui/app.py
+++ b/src/ui/app.py
@@ -8,22 +8,17 @@ from ui.widgets.channel import Channel
 
 from project import ProjectChannel
 
-from song_player import SongPlayer
-
 
 class AppUI(App):    
     CSS_PATH = "../assets/style.tcss"
     
     theme = "tokyo-night"
-    #ENABLE_COMMAND_PALETTE = False
     
     def __init__(self, project):
         super().__init__()
         self.zoom_level = 0.05
         self.last_zoom_level = self.zoom_level
         self.project = project
-        
-        self.song_player = SongPlayer(self)
     
     def create_channel(self, name: str):
         self.query_one("#channels").mount(Channel(
@@ -36,9 +31,6 @@ class AppUI(App):
             name
         ))
     
-    def on_mount(self):
-        self.song_player.play_song(self.app.project)
-    
     def compose(self) -> ComposeResult:
         with Tabs(id="top-menu"):
             yield Tab("File")
diff --git a/src/ui/widgets/channel.py b/src/ui/widgets/channel.py
index 8a630e7..d5762ba 100644
--- a/src/ui/widgets/channel.py
+++ b/src/ui/widgets/channel.py
@@ -54,6 +54,14 @@ class Channel(VerticalGroup):
         self.solo = solo
         self.pan = pan
         self.volume = volume
+
+    def on_checkbox_changed(self, event: Checkbox.Changed):
+        if event.checkbox.id == "mute":
+            self.muted = event.value
+            
+            self.app.query_one("#timeline").query_one()
+        elif event.checkbox.id == "solo":
+            self.solo = event.value
         
     def on_slider_changed(self, event: Slider.Changed):
         if event.slider.id == "volume":
diff --git a/src/ui/widgets/project_settings.py b/src/ui/widgets/project_settings.py
index e3a9f98..a5e361e 100644
--- a/src/ui/widgets/project_settings.py
+++ b/src/ui/widgets/project_settings.py
@@ -2,6 +2,8 @@ from textual.containers import Horizontal
 from textual.app import ComposeResult
 from textual.widgets import Button, Input, Static
 
+import sounddevice as sd
+
 
 class ProjectSettings(Horizontal):
     DEFAULT_CSS = """
@@ -37,6 +39,10 @@ class ProjectSettings(Horizontal):
     def __init__(self):
         super().__init__()
         self.border_title = "Project"
+        
+    def on_button_pressed(self, event: Button.Pressed):
+        if event.button.id == "play-button":
+            sd.play(self.app.project.render())
     
     def compose(self) -> ComposeResult:
         yield Button("▶", tooltip="Play song", flat=True, id="play-button", variant="success") # icon becomes "⏸" when song is playing
diff --git a/src/ui/widgets/timeline.py b/src/ui/widgets/timeline.py
index 2b634bd..f166eff 100644
--- a/src/ui/widgets/timeline.py
+++ b/src/ui/widgets/timeline.py
@@ -14,17 +14,27 @@ class TimelineRow(Horizontal):
         background: $surface-lighten-1;
         height: 8;
         margin-bottom: 1;
-        width: 100;
+        
+        &.-muted {
+            background: $error 25%;
+        }
+        
+        &.-solo {
+            background: $warning 25%;
+        }
     }
     """
 
 class Timeline(Vertical):
     DEFAULT_CSS = """
     Timeline {
+        overflow-x: auto;
+        
         #rows {
             hatch: "-" $surface-lighten-1;
             padding: 0 0;
-            overflow-x: auto;
+            
+            
             
             .beat-line {
                 color: $surface-lighten-1;
@@ -58,6 +68,9 @@ class Timeline(Vertical):
     def calc_bar_offset(self):
         self.bar_offset = self.app.project.bpm / 8 * (0.03333333333 / self.app.zoom_level)
         
+        for row in self.query(TimelineRow):
+            row.styles.width = self.bar_offset * self.app.project.song_length
+        
     @on(events.MouseScrollDown)
     async def mouse_scroll_down(self, event: events.MouseScrollDown):
         self.app.zoom_level += (self.app.scroll_sensitivity_x / 200)
@@ -93,18 +106,17 @@ class Timeline(Vertical):
         
         
         with VerticalScroll(id="rows"):
-            
-            
-            
             for channel in self.app.project.channels:
-                with TimelineRow():
+                with TimelineRow() as row:
+                    row.styles.width = self.bar_offset * self.app.project.song_length
+                    
                     for chunk in channel.chunks:
                         if chunk.chunk_type == ChunkType.CHUNK:
                             yield Chunk(chunk_name=chunk.name, bar_pos=chunk.position)
                         elif chunk.chunk_type == ChunkType.AUDIO:
                             yield AudioChunk(chunk.audio_data, chunk.sample_rate, chunk.name, chunk.position)
 
-            for i in range(1, 17):
+            for i in range(1, self.app.project.song_length):
                 bar = None
                 if i % 4 == 0:
                     bar = Rule.vertical(classes="bar-line", line_style="double")