I type la in console, press 3 to select What Is Pootis, tap + and it does nothing.
Please help.

1) Does HLDJ launch the game correctly for you? Yes
2) Does "HLDJ Loaded Successfully" appear in console on starting the game (with no errors)? Yes, no errors at all

3) What is the console output after selecting a song, or issuing other HLDJ commands such as "hldj_next"? No music, at all! My mic sign shows though and sounds from the game go can be heard!
4) Create your own local server and set the appropriate sv_ commands (see above), then:
4-a) Load one of the sample audio files and perform a search of your Steam directory (without stopping HLDJ) for the file "voice_input.wav" - does it show up, and if so, where? It came up as a shortcut in C:\Program Files (x86)\Steam\steamapps\the_pie_dude\team fortress 2
4-b) If it exists, open it in an audio player: does it sound like the audio file you loaded? Yes, sounds exactly like it's supposed to
4-c) If it exists, return to the game, and enter the following into console:
voice_inputfromfile 1; voice_loopback 1; voice_forcemicrecord 0; voice_modenable 1; voice_enable 1; +voicerecord
Does the audio file start to play? No, not at all.
5) Does voice normally work for you? If not, or you do not have a microphone, have you remembered to set up any applicable options in your operating system and/or the game? * Yes, I use my mic a lot to talk with friends. I have a mic and it is set up.