Versatile Artists' Filters for Variety in Music Playlists

I loaded my IPod with my collected music. As mentioned in my earlier post, I am yet to work on standardizing the mp3 tags so to structure and search my music better. But I thought I could listen to my entire collection. Another daunting problem surfaced, partly because of my swinging moods when listening to music. Consider the following playlist specifications that I would love to give:

• Listen to A. R. Rehman's compositions
• Listen to all Shahrukh Khan's songs
• Listen to songs sung by Hari Haran and Shankar Mahadevan.
• Listen to all songs of 1990's (1990-2000) time for old time's nostalgia.
• Listen to duets (sung by a male and female singer)
• Listen to songs sung by single artists
• Listen to all telugu songs sung by Chitra
• Listen to all tamil songs of Rajnikanth (yes, i listen to telugu, tamil, hindi and english songs)
  
• and so on. But you get the general idea, right?

I listen to songs in RealPlayer, ITunes, Rhapsody and WinAmp, but I am not aware of having the option to get such queries executed for a different playlist according to my choice. And in iPod too there's no such option.

Such queries might be tough right now because the mp3 songs do not have the option to have all such information. For my queries to come to life, we need extra information such as:

singers tagged with (male/female), language of the song, actors/actresses in the song, composed by or music director and comprehensive genre. The genre field in mp3 tags usually takes it just as a single value i.e. movie, inspirational and movie, blues are considered two different genres. But songs of these genres are movie songs, so when there's a query that asks for just movie songs, songs belonging to both these genres should be collected in the playlist. Genre should ideally have a taxonomy, something like a broad category as to what type of music it is (movie, pop, rock, jazz, classical), followed by language in which it is sung (can take one or more values: english, hindi, telugu, tamil), followed by mood of the song (blues, tragedy, philosophical, inspirational and so on).

Currently, ID3 tags do not offer such flexibility. But can we store something in the 'Comments' field and make it possible to run such queries to generate dynamic playlists. Ofcourse, we also need a software that can read the 'Comments' field (or whatever we choose to) and filter out the songs that satisfy the query. I wonder why this requirement of dynamic playlists has not come up yet. Or did it and I am not aware of it? Let me know, while for a good solution to this, I mine.