Redacted (RED) is a general music tracker, and is generally seen as the successor to the late What.CD.
Getting an account
Redacted recruits Power Users on most reputable trackers. Users of the Power User rank and above also get a small number of invites every month to send to friends.
Like What.CD, Redacted offers IRC interviews. More information about that can be found on the interview preparation website.
Some sections of the interview are more important than others. For example, missing a question about trumping might get you a reminder to re-read the rules while missing a question about transcoding will be an automatic fail.
Here's some questions taken from real interviews so you can test yourself:
And here's some past interviews with dialogue between the interviewer and interviewee included: