Audio player with large database. Language advice

See more:

PHP

MySQL

Ruby

audio

HTML5

Rails

, +

I'm working on a new website which makes sending music between music professionals easier. Some receive more than 1000 songs a week and I want to simplify this.
In short the website contains out of two sections. One to send music and the second to receive music (some sort of iTunes but then online).

The process is as following:

- X needs to be able to insert all the required data (artist, name track, genre etc etc) and upload his music to Y via our server. The track information needs to be stored in the MP3 tag
- Y receives email notification
- Y receives the music in his online audio player
- Y can play music and download music directly from audio player

The system must be able to handle 1 million songs a year. Which languages are the most important when building this?