Create a file called lastfm.cs beside your checkout, or any any parent directory above it:
namespace Tunez
{
public static class LastFMAppCredentials
{
public const string ApplicationName = "APPNAME";
public const string APIKey = "APIKEY";
public const string SharedSecret = "SECRET";
public const string RegisteredTo = "NAME";
}
}
If you register a last.fm api key this will be where you need to place the details.