diff --git a/app/app.css b/app/app.css
index f535a1b..a946b97 100644
--- a/app/app.css
+++ b/app/app.css
@@ -4,14 +4,13 @@ body {
   flex-direction: column;
   height: 100vh;
 }
-header,
-footer {
+body > header,
+body > footer {
   box-shadow: 0 0 3px #000;
 }
 main {
   flex-grow: 1;
-  overflow-x: hidden;
-  overflow-y: auto;
+  overflow: hidden;
 }
 nav ul {
   margin: 0;
@@ -51,7 +50,19 @@ nav ul li.active {
 #player:not([data-flags~=repeat]) .repeat {
   opacity: 0.5;
 }
+.component {
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+}
+#queue {
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+}
 #queue ul {
+  flex-grow: 1;
+  overflow: auto;
   list-style: none;
   margin: 0;
   padding: 0;
@@ -69,3 +80,15 @@ nav ul li.active {
 #queue .current {
   font-weight: bold;
 }
+#library {
+  height: 100%;
+  display: flex;
+  flex-direction: column;
+}
+#library ul {
+  flex-grow: 1;
+  overflow: auto;
+  list-style: none;
+  margin: 0;
+  padding: 0;
+}
diff --git a/app/css/app.less b/app/css/app.less
index 31f162c..ae523e4 100644
--- a/app/css/app.less
+++ b/app/css/app.less
@@ -3,13 +3,16 @@ body {
 	display: flex;
 	flex-direction: column;
 	height: 100vh;
+
+	> header, > footer {
+		box-shadow: 0 0 3px #000;
+	}
 }
 
-header, footer {
-	box-shadow: 0 0 3px #000;
-}
 
 @import "main.less";
 @import "nav.less";
 @import "player.less";
+@import "component.less";
 @import "queue.less";
+@import "library.less";
diff --git a/app/css/component.less b/app/css/component.less
new file mode 100644
index 0000000..798a0c4
--- /dev/null
+++ b/app/css/component.less
@@ -0,0 +1,5 @@
+.component {
+	height: 100%;
+	display: flex;
+	flex-direction: column;
+}
\ No newline at end of file
diff --git a/app/css/library.less b/app/css/library.less
new file mode 100644
index 0000000..85b6727
--- /dev/null
+++ b/app/css/library.less
@@ -0,0 +1,14 @@
+#library {
+	.component;
+
+	ul {
+		flex-grow: 1;
+		overflow: auto;
+		list-style: none;
+		margin: 0;
+		padding: 0;
+	}
+
+	li {
+	}
+}
diff --git a/app/css/main.less b/app/css/main.less
index ce5e90f..394f547 100644
--- a/app/css/main.less
+++ b/app/css/main.less
@@ -1,5 +1,4 @@
 main {
 	flex-grow: 1;
-	overflow-x: hidden;
-	overflow-y: auto;
+	overflow: hidden;
 }
diff --git a/app/css/queue.less b/app/css/queue.less
index 6fecff0..46e051a 100644
--- a/app/css/queue.less
+++ b/app/css/queue.less
@@ -1,5 +1,9 @@
 #queue {
+	.component;
+
 	ul {
+		flex-grow: 1;
+		overflow: auto;
 		list-style: none;
 		margin: 0;
 		padding: 0;
diff --git a/app/index.html b/app/index.html
index 19b44ae..8cf6767 100644
--- a/app/index.html
+++ b/app/index.html
@@ -24,9 +24,19 @@
 			</section>
 		</header>
 		<main>
-			<section id="queue"></section>
+			<section id="queue">
+				<header></header>
+				<ul></ul>
+			</section>
 			<section id="playlists"></section>
-			<section id="library"></section>
+			<section id="library">
+				<header></header>
+				<ul></ul>
+			</section>
+			<section id="fs">
+				<header></header>
+				<ul></ul>
+			</section>
 			<section id="misc"></section>
 		</main>
 		<footer>
@@ -35,6 +45,7 @@
 					<li data-for="queue">Q</li>
 					<li data-for="playlists">Playlists</li>
 					<li data-for="library">Library</li>
+					<li data-for="fs">FS</li>
 					<li data-for="misc">Misc</li>
 				</ul>
 			</nav>
diff --git a/app/js/app.js b/app/js/app.js
index cea3180..ffa26b6 100644
--- a/app/js/app.js
+++ b/app/js/app.js
@@ -3,8 +3,10 @@ import * as mpd from "./lib/mpd.js";
 import * as player from "./player.js";
 
 import * as queue from "./queue.js";
+import * as library from "./library.js";
+import * as fs from "./fs.js";
 
-const components = { queue };
+const components = { queue, library, fs };
 
 export function activate(what) {
 	for (let id in components) {
@@ -29,8 +31,7 @@ async function init() {
 	await mpd.init();
 	player.init(document.querySelector("#player"));
 
-	activate("queue");
-	window.mpd = mpd;
+	activate("fs");
 }
 
 
diff --git a/app/js/fs.js b/app/js/fs.js
new file mode 100644
index 0000000..5781188
--- /dev/null
+++ b/app/js/fs.js
@@ -0,0 +1,65 @@
+import * as app from "./app.js";
+import * as mpd from "./lib/mpd.js";
+import * as html from "./lib/html.js";
+import * as player from "./player.js";
+import * as format from "./lib/format.js";
+import * as ui from "./lib/ui.js";
+
+let node;
+const SORT = "-Track";
+
+function buildHeader(path) {
+	filter = filter || {};
+	let header = node.querySelector("header");
+	html.clear(header);
+
+	let button = html.button({}, "Music Library", header);
+	button.addEventListener("click", e => listArtists());
+
+	let artist = filter["Artist"];
+	if (artist) {
+		let artistFilter = {"Artist":artist};
+		let button = html.button({}, artist, header);
+		button.addEventListener("click", e => listAlbums(artistFilter));
+
+		let album = filter["Album"];
+		if (album) {
+			let albumFilter = Object.assign({}, artistFilter, {"Album":album});
+			let button = html.button({}, album, header);
+			button.addEventListener("click", e => listSongs(albumFilter));
+		}
+	}
+}
+
+function buildDirectory(data, parent) {
+	let path = data["directory"];
+	let node = ui.group(path, {}, parent);
+	node.addEventListener("click", e => list(path));
+	return node;
+}
+
+function buildFile(data, parent) {
+	return ui.song(data, parent);
+}
+
+function buildResults(results) {
+	let ul = node.querySelector("ul");
+	html.clear(ul);
+
+	results["directory"].forEach(directory => buildDirectory(directory, ul));
+	results["file"].forEach(file => buildFile(file, ul));
+}
+
+async function list(path) {
+	let results = await mpd.listPath(path);
+	buildResults(results);
+//	buildHeader(path);
+}
+
+export async function activate() {
+	list("");
+}
+
+export function init(n) {
+	node = n;
+}
diff --git a/app/js/lib/art.js b/app/js/lib/art.js
index db9d5f2..00b4207 100644
--- a/app/js/lib/art.js
+++ b/app/js/lib/art.js
@@ -15,19 +15,6 @@ function load(key) {
 	return localStorage.getItem(`${STORAGE_PREFIX}-${key}`);
 }
 
-async function getImageData(songUrl) {
-	let data = [];
-	let offset = 0;
-	while (1) {
-		let params = ["albumart", `"${mpd.escape(songUrl)}"`, offset];
-		let lines = await mpd.command(params.join(" "));
-		data = data.concat(lines[2]);
-		let metadata = parser.linesToStruct(lines.slice(0, 2));
-		if (data.length >= Number(metadata["size"])) { return data; }
-		offset += Number(metadata["binary"]);
-	}
-}
-
 async function bytesToImage(bytes) {
 	let blob = new Blob([bytes]);
 	let src = URL.createObjectURL(blob);
@@ -62,7 +49,7 @@ export async function get(artist, album, songUrl = null) {
 	cache[key] = promise;
 
 	try {
-		let data = await getImageData(songUrl);
+		let data = await mpd.albumArt(songUrl);
 		let bytes = new Uint8Array(data);
 		let image = await bytesToImage(bytes);
 		let url = resize(image).toDataURL(MIME);
diff --git a/app/js/lib/mpd.js b/app/js/lib/mpd.js
index fc1adea..f14b521 100644
--- a/app/js/lib/mpd.js
+++ b/app/js/lib/mpd.js
@@ -34,7 +34,19 @@ function processQueue() {
 	ws.send(current.cmd);
 }
 
-export function escape(str) {
+function serializeFilter(filter) {
+	let tokens = ["("];
+	Object.entries(filter).forEach(([key, value], index) => {
+		index && tokens.push(" AND ");
+		tokens.push(`(${key} == "${value}")`);
+	});
+	tokens.push(")");
+
+	let filterStr = tokens.join("");
+	return `"${escape(filterStr)}"`;
+}
+
+function escape(str) {
 	return str.replace(/(['"\\])/g, "\\$1");
 }
 
@@ -54,7 +66,10 @@ export async function commandAndStatus(cmd) {
 
 export async function status() {
 	let lines = await command(["status", "currentsong"]);
-	return parser.linesToStruct(lines);
+	let status = parser.linesToStruct(lines);
+	// duration returned 2x => arrayfied
+	if ("duration" in status) { status["duration"] = status["duration"][0]; }
+	return status;
 }
 
 export async function listQueue() {
@@ -62,6 +77,55 @@ export async function listQueue() {
 	return parser.songList(lines);
 }
 
+export async function enqueue(fileOrFilter, sort = null) {
+	if (typeof(fileOrFilter) == "string") {
+		return command(`addid "${escape(fileOrFilter)}"`);
+	}
+
+	let tokens = ["findadd"];
+	tokens.push(serializeFilter(fileOrFilter));
+//	sort && tokens.push("sort", sort);  FIXME not implemented in MPD
+	return command(tokens.join(" "));
+}
+
+export async function listPath(path) {
+	let lines = await command(`lsinfo "${escape(path)}"`);
+	return parser.pathContents(lines);
+}
+
+export async function listTags(tag, filter = null) {
+	let tokens = ["list", tag];
+	if (filter) {
+		tokens.push(serializeFilter(filter));
+
+		let fakeGroup = Object.keys(filter)[0]; // FIXME hack for MPD < 0.21.6
+		tokens.push("group", fakeGroup);
+	}
+	let lines = await command(tokens.join(" "));
+	let parsed = parser.linesToStruct(lines);
+	return [].concat(parsed[tag] || []);
+}
+
+export async function listSongs(filter) {
+	let tokens = ["find"];
+	tokens.push(serializeFilter(filter));
+	let lines = await command(tokens.join(" "));
+	return parser.songList(lines);
+}
+
+export async function albumArt(songUrl) {
+	let data = [];
+	let offset = 0;
+	while (1) {
+		let params = ["albumart", `"${escape(songUrl)}"`, offset];
+		let lines = await command(params.join(" "));
+		data = data.concat(lines[2]);
+		let metadata = parser.linesToStruct(lines.slice(0, 2));
+		if (data.length >= Number(metadata["size"])) { return data; }
+		offset += Number(metadata["binary"]);
+	}
+}
+
 export async function init() {
 	return new Promise((resolve, reject) => {
 		try {
diff --git a/app/js/lib/parser.js b/app/js/lib/parser.js
index be08a9e..7439962 100644
--- a/app/js/lib/parser.js
+++ b/app/js/lib/parser.js
@@ -3,7 +3,18 @@ export function linesToStruct(lines) {
 	lines.forEach(line => {
 		let cindex = line.indexOf(":");
 		if (cindex == -1) { throw new Error(`Malformed line "${line}"`); }
-		result[line.substring(0, cindex)] = line.substring(cindex+2);
+		let key = line.substring(0, cindex);
+		let value = line.substring(cindex+2);
+		if (key in result) {
+			let old = result[key];
+			if (old instanceof Array) {
+				old.push(value);
+			} else {
+				result[key] = [old, value];
+			}
+		} else {
+			result[key] = value;
+		}
 	});
 	return result;
 }
@@ -16,6 +27,7 @@ export function songList(lines) {
 		if (line.startsWith("file:") && batch.length) { 
 			let song = linesToStruct(batch);
 			songs.push(song);
+			batch = [];
 		}
 		batch.push(lines.shift());
 	}
@@ -26,4 +38,28 @@ export function songList(lines) {
 	}
 
 	return songs;
+}
+
+export function pathContents(lines) {
+	const prefixes = ["file", "directory", "playlist"];
+
+	let batch = [];
+	let result = {};
+	let batchPrefix = null;
+	prefixes.forEach(prefix => result[prefix] = []);
+
+	while (lines.length) {
+		let line = lines[0];
+		let prefix = line.split(":")[0];
+		if (prefixes.includes(prefix)) { // begin of a new batch
+			if (batch.length) { result[batchPrefix].push(linesToStruct(batch)); }
+			batchPrefix = prefix;
+			batch = [];
+		}
+		batch.push(lines.shift());
+	}
+
+	if (batch.length) { result[batchPrefix].push(linesToStruct(batch)); }
+
+	return result;
 }
\ No newline at end of file
diff --git a/app/js/lib/ui.js b/app/js/lib/ui.js
new file mode 100644
index 0000000..e1b3845
--- /dev/null
+++ b/app/js/lib/ui.js
@@ -0,0 +1,47 @@
+import * as mpd from "./mpd.js";
+import * as html from "./html.js";
+
+function playButton(fileOrFilter, parent) {
+	let button = html.button({}, "▶", parent);
+	button.addEventListener("click", async e => {
+		e.stopPropagation();
+		await mpd.command("clear");
+		await mpd.enqueue(fileOrFilter, SORT);
+		await mpd.command("play");
+		app.activate("queue");
+		player.update();
+	});
+	return button;
+}
+
+function addButton(fileOrFilter, parent) {
+	let button = html.button({}, "+", parent);
+	button.addEventListener("click", async e => {
+		e.stopPropagation();
+		await mpd.enqueue(fileOrFilter, SORT);
+		// fixme notification?
+	});
+	return button;
+}
+
+
+export function song(data, parent) {
+	let node = html.node("li", {}, "", parent);
+
+	let file = data["file"];
+	playButton(file, node);
+	addButton(file, node);
+
+	html.node("h3", {}, data["Title"], node);
+
+	return node;
+}
+
+export function group(label, filter, parent) {
+	let node = html.node("li", {}, label, parent);
+
+	playButton(filter, node);
+	addButton(filter, node);
+
+	return node;
+}
\ No newline at end of file
diff --git a/app/js/library.js b/app/js/library.js
new file mode 100644
index 0000000..b5d3547
--- /dev/null
+++ b/app/js/library.js
@@ -0,0 +1,93 @@
+import * as app from "./app.js";
+import * as mpd from "./lib/mpd.js";
+import * as html from "./lib/html.js";
+import * as player from "./player.js";
+import * as format from "./lib/format.js";
+import * as ui from "./lib/ui.js";
+
+let node;
+const SORT = "-Track";
+
+function buildHeader(filter) {
+	filter = filter || {};
+	let header = node.querySelector("header");
+	html.clear(header);
+
+	let button = html.button({}, "Music Library", header);
+	button.addEventListener("click", e => listArtists());
+
+	let artist = filter["Artist"];
+	if (artist) {
+		let artistFilter = {"Artist":artist};
+		let button = html.button({}, artist, header);
+		button.addEventListener("click", e => listAlbums(artistFilter));
+
+		let album = filter["Album"];
+		if (album) {
+			let albumFilter = Object.assign({}, artistFilter, {"Album":album});
+			let button = html.button({}, album, header);
+			button.addEventListener("click", e => listSongs(albumFilter));
+		}
+	}
+}
+
+function buildAlbum(album, filter, parent) {
+	let childFilter = Object.assign({}, filter, {"Album": album});
+	let node = ui.group(album, childFilter, parent);
+	node.addEventListener("click", e => listSongs(childFilter));
+	return node;
+}
+
+function buildArtist(artist, filter, parent) {
+	let childFilter = Object.assign({}, filter, {"Artist": artist});
+	let node = ui.group(artist, childFilter, parent);
+	node.addEventListener("click", e => listAlbums(childFilter));
+	return node;
+}
+
+function buildSongs(songs, filter) {
+	let ul = node.querySelector("ul");
+	html.clear(ul);
+
+	songs.map(song => ui.song(song, ul));
+}
+
+function buildAlbums(albums, filter) {
+	let ul = node.querySelector("ul");
+	html.clear(ul);
+
+	albums.map(album => buildAlbum(album, filter, ul));
+}
+
+function buildArtists(artists, filter) {
+	let ul = node.querySelector("ul");
+	html.clear(ul);
+
+	artists.map(artist => buildArtist(artist, filter, ul));
+}
+
+async function listSongs(filter) {
+	let songs = await mpd.listSongs(filter);
+	buildSongs(songs, filter);
+	buildHeader(filter);
+}
+
+async function listAlbums(filter) {
+	let albums = await mpd.listTags("Album", filter);
+	buildAlbums(albums, filter);
+	buildHeader(filter);
+}
+
+async function listArtists(filter) {
+	let artists = await mpd.listTags("Artist", filter);
+	buildArtists(artists, filter);
+	buildHeader(filter);
+}
+
+export async function activate() {
+	listArtists();
+}
+
+export function init(n) {
+	node = n;
+}
diff --git a/app/js/queue.js b/app/js/queue.js
index c28e169..895b456 100644
--- a/app/js/queue.js
+++ b/app/js/queue.js
@@ -44,12 +44,11 @@ function buildSong(song) {
 }
 
 function buildSongs(songs) {
-	html.clear(node);
+	let ul = node.querySelector("ul");
+	html.clear(ul);
 
-	let ul = html.node("ul");
 	songs.map(buildSong).forEach(li => ul.appendChild(li));
 
-	node.appendChild(ul);
 	updateCurrent();
 }