Case Study: NADJ Radio – An AI-Presented Radio Automation Platform

Client: National Association of Disc Jockeys (NADJ) CIC
Delivered by: WD82 Ltd
Platform: Windows desktop playout engine with browser and phone control
Status: Built and tested

NADJ Radio is a complete radio automation and playout platform built by WD82 Ltd for the National Association of Disc Jockeys. It schedules music, mixes and station imaging around a programme clock, then streams the finished output to an internet radio host. Alongside the music, an AI presenter introduces songs, and AI voices read the news, weather and travel. The platform runs as a single application on a standard Windows PC and can be controlled from any browser or phone.

The purpose

NADJ is a UK trade body for professional DJs. A station of its own gives the association a voice. It can showcase members' mixes and promote the association's articles and events. It can also play the kind of music its members actually play, around the clock.

Running a 24-hour station has traditionally meant one of two things: paying presenters, or using commercial playout software with licence fees and a steep learning curve. Even then, an automated station tends to sound like a jukebox: songs back to back, no personality, no local information.

The brief was to build a station that sounds presented rather than automated, run by one person, on hardware NADJ already owns:

• Sound like a real radio station: tight joins, no silence, a proper end to every hour, and timed breaks for news and adverts.
• Give it a presenter: links between songs, mix introductions, and time and day awareness, without hiring anyone.
• Keep listeners informed: news, UK weather and motorway travel read out in natural voices.
• Showcase members: member mixes credited on air, and a Top 40 show built from the NADJ chart.
• Be manageable by one person from an iPad or phone, with clear warnings when something needs attention.

The challenge

Radio is unforgiving: a second of silence is noticeable and a link spoken over the weather is jarring. The same mix playing at the same time every day gets noticed too. The hard part of this project was not playing audio files. It was making hundreds of small editorial decisions every hour, the way an experienced programme controller would, and doing it reliably.

The music library is around a terabyte, spread across many folders: current releases, throwbacks, mash-ups, extended mixes, and Mastermix and Grandmaster megamixes. Each needed its own rules. The station also had to cope with the real world. Internet feeds drop out, a news bulletin arrives late, and listeners hear the stream a few seconds behind the studio clock.

The solution

WD82 Ltd designed and built NADJ Radio from the ground up as a self-contained playout engine. It plans each hour in advance against a programme clock, mixes the audio itself, and streams the result in real time. Every spoken element is written and voiced by AI services and placed precisely into the mix.

1. Programme clock and intelligent rotation

• Timed programme clock: the top-of-hour ident, news, and set breaks at :20 and :40 for adverts and long-form mixes, with music rotation in between.
• Every song before any repeats: each folder is played through in full before a track returns, where practicable, with artist and track separation rules on top.
• Multi-folder rotation: sources that combine folders (for example mash-ups and word-play) alternate between them, picking at random within each.
• No same-time repeats: a mix will not return at the same time of day within the past week, so regular listeners never hear the same thing at the same time each day.
• Content safeguards: explicit and "dirty" versions are filtered out. Extended remixes are kept out of normal rotation. Christmas songs only play in December.
• Long-mix handling: megamixes too long for one slot are split across hours and carry on from where they left off. The on-screen playlist shows which segment is playing.

2. A seamless end to every hour

Every hour closes with an end-of-hour (EOH) track timed to finish exactly on the hour. The planner fills the hour up to it with songs, imaging, or a song faded early, so there is no dead air in front of it. A safety net checks every few seconds that each upcoming hour still ends correctly, and repairs the plan if an edit has disturbed it. In planning simulations over 96 consecutive hours, every hour ended on the EOH, exactly on the hour, with no gaps.

3. The AI presenter

• Song links: back-announces the previous track and introduces the next, using real facts about the artist and song (release year, album, background), and "on this day" anniversaries where relevant.
• Day awareness: the first link of each hour opens with a light, human touch, such as "How's your Tuesday going?"
• Mix introductions: each long-form mix gets its own introduction, including its length, its collection and, for a split mix, where it picks up.
• Station messages: promotional messages and web addresses are woven into links naturally, rather than as separate adverts.
• Broadcast timing: links are placed over a song's intro and wait for any weather read, imager or advert to finish first. A longer link starts over the end of the previous song, or is read before the song over a music bed.
• Typed voice tracking: the operator can type a message from the control panel and have it read on air as a presenter link.

4. News, weather and travel read by AI voices

• News: scheduled news bulletins played over a music bed, plus the latest NADJ articles read on air from the association's own website.
• Weather: a UK-wide forecast taken from live weather data and turned into a natural spoken script.
• Travel: major UK motorway incidents and closures from the National Highways live data feed, written up as a spoken bulletin. AI rewording is checked so it can never add or change a road, junction or cause.
• Time checks: pre-recorded in a chosen neural voice and dropped in at set points in the hour.

5. Shows, charts and members

• NADJ Top 40: a countdown show built automatically from the NADJ Chart Feeds. The presenter reads only the position, the movement ("up 1", "down 7", "new entry"), the intro and the outro.
• Member mixes: credited on air with the member's name.
• Scheduled shows: weekly shows can be locked to a time slot. A live DJ takeover is protected by a password.
• Recordings: any hour can be recorded with a tracklist and published to Mixcloud from inside the app.

6. Studio, control and reliability

• Browser studio: a live playlist showing each item's genre, key and BPM, link status, the newest 24 tracks highlighted, and Replace and Remove controls.
• Remote control: from a phone on the local network, or securely from anywhere through a private network connection.
• Runs unattended: starts with Windows, keeps playing when the user signs out, and restarts automatically if it ever stops.
• Listener sync: the station clock is corrected at the end of each hour, so listeners, who hear the stream a few seconds late, still hear the news exactly on the hour.
• Clear diagnostics: every warning says what happened and what to do, in plain English.

The APIs behind the station

NADJ Radio brings together a set of external services, each doing one job well. Every key is stored securely on the station PC and kept out of settings exports.

How it was developed

NADJ Radio was built in short, focused releases. Each one fixed or added something specific, and each was tested before handover. Every release came with release notes and a test report written in plain English, so it was always clear what had changed and what had been checked.

The development followed a simple loop:

1. Listen: real behaviour was reported in broadcast terms, such as "the link came in over the weather" or "the same mix at 12:03 four days running".
2. Reproduce: the exact running order was recreated in an automated test before any change was made.
3. Fix the cause, not the symptom: a link landing in the wrong place, for example, was traced to the moment items were added in front of a mix after its introduction had been written.
4. Prove it: the new test, the full suite of 630+ tests and, for scheduling changes, simulations of up to 96 consecutive planned hours.

This approach produced a large safety net. Rules for repeats, the end of the hour, link timing and same-time protection are each covered by tests that recreate real situations. Future changes can then be made with confidence that earlier fixes stay fixed.

Built-in safeguards

• API keys and passwords are kept out of settings exports and never shown in full.
• The control page only accepts connections from the station PC itself, or through the secure remote link.
• AI output is checked before it goes on air. A reply that is too short, names the wrong song or adds travel details that weren't in the data is replaced with safe standard wording.
• If a voice service fails, the station falls back to another voice instead of going silent.

Estimated project cost

The figures below estimate what a project of this scope would cost if commissioned from a UK software developer or agency at typical rates of £450–£550 per developer day. They are an estimate for comparison, not an invoice.

Ongoing running costs are modest because the station runs on existing hardware. The main costs are:

• the stream host subscription;
• pay-as-you-go AI usage for writing and voicing links and bulletins, typically a small monthly amount that depends on how often links are set to play;
• music licensing, which any station needs.

Weather, travel and music-fact data come from free public services.

The outcome

NADJ Radio has been built and tested as a complete, presenter-style station in a box. It schedules a balanced, varied mix of music across a large library and closes every hour cleanly. Its AI presenter knows what it is playing and what day it is. News, weather and travel are read by natural voices, and one person can run it all from an iPad.

For NADJ, it means a professional-sounding station without presenter costs or a playout licence, and a platform that showcases members' mixes and the association's own content. The groundwork is also in place for the next steps under consideration: running playout online, reading the library directly from cloud storage, and streaming to the association's own server.