Arc

Ceremony playlist tools
for your Spotify library

Free tools for facilitators who play music in ceremonies, retreats and other long events. They work with your own Spotify playlists, and everything they make goes straight into your Spotify library.

Requires Spotify Premium

Tools available now

About this app

What it does
Arc makes long playlists from your existing Spotify playlists. Describe the structure of the playlists you want to create, and this app builds as many complete playlists as your music allows, with songs picked at random and no song repeated across the playlists made from one recipe. Each playlist is created in your Spotify account, ready to play.

What it's good for
Ceremonies, retreats, workshops, and any long event where the music should follow an arc, such as arriving, deepening, and landing. Instead of steering a shuffle during the event or manually building a playlist ahead of time for each event, set the structure once and get multiple fresh, non-overlapping playlists. You can then use these playlists for subsequent events without ever repeating the same music.

How it works

Connect to Spotify through a free developer app. This takes a few minutes to set up, but you’ll only need to do it once.
Define your recipe(s): which of your playlists to draw from, in what order, and for how long.
Build the playlists. This app shows you what it found and asks before it builds anything.

What you need
A Spotify Premium account (Spotify requires it for the free developer app) and some playlists of your own to draw from.

Reporting problems
If you run into a problem, choose Report a problem in the app menu.

Privacy
Your existing Spotify playlists are only read, never changed. Everything runs in this browser, and nothing about your music, such as playlist names or songs, goes anywhere except to you and Spotify. For the full details, see Privacy.

One-time setup

Have you done this setup before?

Either way, you will get clear step-by-step instructions. You will switch between this tab and Spotify's, so keep both open.

What does all this actually do?

Spotify keeps your music private, so this page can only reach your playlists if you give it permission. Making a Spotify developer app inside your Spotify account is how you give this page that permission.

The Client ID works like a name tag. It tells Spotify who is asking for access, and Spotify then asks you to approve it. After that, this page can look at your playlists and make new ones in your account. Only you can use the app you made inside your Spotify account.

Your Client ID is not a secret. It stays in this browser and goes only to Spotify. You do this once. If you want to use Arc on another device, you won't need to create another app, just use the same Client ID.

Arc

Ceremony playlist tools for your Spotify library

2. Edit your recipes

How recipes work

A recipe describes one kind of playlist: which of your playlists to draw from, in what order, and for how long. The app makes as many playlists from a recipe as your songs allow, and no song repeats between them.

Segments

Each row is one stretch of music. Tap the playlist to choose it, and use the minus and plus buttons to set how many minutes it fills. Drag the dotted handle to change the order. Each segment typically lands within about 30 seconds of its target. Point at a row, or tap a piece of the bar at the top, to see which belongs to which. Add another with New segment.

Silence

The small tags hanging off the right side of the rows are silences. A silence adds time on top of your segment minutes, and can be used for effect or simply to tell a facilitator the music has moved into a new segment. To put the same silence between every two segments, set the length at the bottom of the recipe, beside Duplicate and Delete. Tap a tag to change that one silence. A tag with a changed length is pink, and Reset to default puts it back. To add a silence where there is none, use a segment's three dots.

Mixes

To blend two playlists in one segment, tap the three dots on that row and choose Add a mix. Pick the second playlist, then use the slider to set how much of each. In the bar at the top, a mixed segment shows as diagonal stripes in two shades of the accent color.

A recipe has a size limit, so that it can always be saved. When a recipe is full, New segment and Add a mix are greyed out, and a change that would make it longer is not made, until something is removed.

Names

The name of a recipe is also the name of the playlists it makes: a recipe called "Warm focus" makes "Warm focus 1", "Warm focus 2", and so on. Give every recipe a different name. When you build playlists again, this app treats playlists that match a recipe's name as its own and offers to replace them.

3. Build playlists

Builds playlists for the selected recipe. You can see the plan first, and nothing is built until you confirm.

4. Back up manually to this device (optional)

Your recipes live only on this device. Clearing your browser data would erase them. A manual backup keeps a copy so you can restore them if needed.

Support me

Everyone is welcome to use this app. If it’s been helpful, please give whatever feels right to you.

A guide for facilitators

Designed for long playlists

This app draws songs from playlists you already have. It works best with long playlists, each one a mood or a stage of the ceremony: settling, rising, the peak, landing, rest. A recipe puts them in order and says how long each part lasts. With shorter playlists it might be hard to fill a longer segment of a recipe, and the app won’t be able to build as many playlists out of it.

What it doesn’t do

It doesn’t find new music or sort your library. It only picks from the playlists you have already created, so what plays is always your choice.

Silence between segments

A short silence between segments can do two things:

Give space. One part settles before the next begins.
Help you track time. A short silence can signal to you, the facilitator, that the ceremony is moving into its next segment.

You can use the same length of silence between all segments and you can edit each silence to have a different duration.

One recipe, many playlists

One recipe can build more than one playlist if desired, each with its own unique songs. With 3 playlists, a client can come to 3 ceremonies and never hear the same song twice. Play them in order, one per ceremony.

How many you can build depends on how long your playlists are. Because the app doesn’t repeat songs across playlists, with each new playlist it builds it is left with fewer songs to draw from for the next playlist it builds. Eventually, it won’t have enough songs to fill a segment. The playlist that runs out of options first determines the maximum number of playlists the app can build for a recipe. For example, in the table below, the recipe can build a maximum of 4 playlists from the given recipe.

Each playlist uses	Available	Enough for
30 minm of Settling	3 hrh 10 minm	6 playlists
2 hrh of Journey	8 hrh 30 minm	4 playlists
40 minm of Landing	3 hrh 50 minm	5 playlists

Adding new music

If, like me, you add new music to your collection over time, I have good news for you: the app can re-build all the playlists it previously built and integrate all your new music into them. If you’ve added enough new music to your collection, it might even be able to build more playlists from a given recipe than it was able to before. This will replace the ones built before with the new music mixed in. A new build starts fresh, so songs from earlier playlists can come back. If a client is partway through a series, finish it before building again. The app gives you an option to keep the previously built playlists when you build new ones.

More options

Build all recipes

Builds, or rebuilds, the playlists for every recipe at once. It shows what it found and asks first, as it does for one recipe.

Remove built playlists

Removes the playlists this app built from a recipe from your Spotify library. Your recipes and your other playlists are not touched. It only looks at playlists that match the recipe’s name, and it asks before removing anything.

Built from

Color

Choose the main color of this page. It's used for buttons, links, and highlights.

Autosave or backup

Your recipes are saved to Spotify automatically, and a change you make on one device shows up on your others. The other choice is a manual backup: you download a file yourself and restore from it later. Changing this is not recommended. With a manual backup, nothing is saved unless you remember to make a backup, so clearing your browser's data can lose your recipes, and your devices will not stay in step.

Change Spotify login

Sign in with a different Spotify account. Spotify’s sign-in page opens, where Not you? lets you choose another account. Your recipes stay as they are and are saved to the account you sign in with.

Sign out and clear data

For when you’re done on a computer that isn’t yours, or when something here isn’t working. This signs you out of Spotify and erases everything this app keeps in this browser: your Client ID, your recipes, and your settings. Nothing in your Spotify account changes.

Your recipes are erased too. To get them back afterward, choose Restore in the app menu and pick the backup you made on this device. If you haven't backed up to this device, choose Back up now there first.

Hide support button

The Support me button stays visible until you have... supported me 🙂. If this app has been helpful to you, please give whatever feels right. Already did? Thank you! Check the box and the button will leave you alone. This runs on the honor system, so nobody’s looking, and the button waits patiently.

I have supported you!

Privacy

What stays in this browser

Your Client ID, your Spotify sign-in, your recipes, the list of your playlists, your color choice, a copy of the songs from your playlists, and a count of the requests this app sends to Spotify (to learn how often Spotify limits them) are saved in this browser, and nowhere else. The saved sign-in lets this app reconnect to Spotify by itself when you come back. The copy of your songs lets this app skip asking Spotify for them again. Sign out and clear data, in More options, removes everything.

Recipes are saved to Spotify unless you choose otherwise: each recipe is also kept in a private playlist in your own Spotify account, in the playlist's description. That is where this app saves it and reads it back, and it goes nowhere else. You can change this at any time in More options.

Your Spotify account

You sign in on Spotify's own page, and this app never sees your Spotify password. It asks Spotify for permission to read your playlists, create playlists, remove playlists, and set their cover images. Your existing playlists are only read, never changed. Removing only touches the playlists this app made, unless you choose to remove others too.

Playlists created by this app stay off your Spotify profile and out of search, though anyone with a playlist's link can still open it. To change that, use Make private in the Spotify app.

Who the page talks to

Spotify, for everything about your music. The page's code comes from GitHub, and the Python it runs comes from a public code host (jsDelivr). Ko-fi's page loads only if you press Support me, and the report form opens only if you choose to report a problem.

Music sharing

Music sharing runs on a small service on Cloudflare, run by the developer of this app. Browsing it sends nothing about you. When you share a playlist, it keeps the playlist's name, its picture's address, your Spotify name (or none, when you share anonymously), the type you chose with its books, phases, mood words or name, the description, its songs as Spotify IDs and recording codes with each song's title, artist and length, how many songs and how long, and the few artists heard most. It does not keep your Spotify username: your temporary sign-in is checked with Spotify and only a scrambled code made from your Spotify ID is kept, so it knows which shares are yours. Stop sharing a playlist and it is deleted.

A report keeps its reason, your note and the same kind of scrambled code, and is emailed to the developer. Adding a shared playlist makes a private copy in your Spotify, and this browser remembers it is a copy so it is not shared again. Nothing records who added what.

A shared playlist's page lists its songs. When you click a song's play button, the app asks Deezer for a 30 second preview of that one song, sending only its recording code. Deezer also sees your internet address, as any site you load does. Nothing goes to Deezer before that.

Anonymous visit counts

The page keeps simple counts, to see how many people use this app and how it is used. It counts visits with GoatCounter, a service that uses no cookies and does not use unique identifiers to follow people around the web. It records that the page was opened, with the browser, screen size, country, and the site you came from, but not who you are. It also counts a few actions: the first time a browser connects to Spotify, how many playlists get created, when Support me is opened, and the kind of connection problem that happened. It never receives playlist names, recipes, song titles, or your Client ID. A small marker in this browser remembers that your first connection was counted, so it is counted once.

Support me

Ko-fi handles any support you give, along with its payment providers, so this app never sees your payment details. If you check "I have supported you!" in More options, that choice is saved in this browser and goes nowhere else.

Problem reports

A problem report is sent only if you choose to send it, and it goes only to me, the developer of this app. The form opens in a new tab, and nothing is sent until you submit it there. The details attached are shown in More options first: the app version, browser, window size, last error, and recent steps. Your sign-in, Client ID, playlist names, and song titles are never included.

Accounts and ads

There are no accounts and no ads.

Setup complete!

Unwrapping the update

Arc

Part of this page did not start

Tools available now

Where it helps

A one-time setup first