Here is a summary of the article in one paragraph: A developer named Nathan Leinz created a project that allows users to send previews of songs via phone call using Twilio, Phoenix, Elixir, and the Spotify API. The project starts with sending an HTTP POST request to a preconfigured URL with song title and requester information, then searching for the song on the Spotify API and fetching a preview URL. The application dispatches a message to Twilio's API, which calls the recipient and plays the song preview. The project uses Elixir and Phoenix as the programming languages and frameworks, and Twilio and ngrok are used for communication with the phone number and tunneling of the HTTP request, respectively. With the help of environmental variables, ExTwilio library, and some routing modifications, the application is able to send messages and make phone calls through Twilio's API.