Make sure you have iTunes on your computer first, as well as an MP3 or WAV of the song you need to convert. Import the audio or music file into iTunes on your PC/Mac, and convert the file to AAC. Rename the file extension to .m4r, followed by syncing the file to your iPhone. If you have GarageBand, there's a feature to save audio as a ringtone.
Kevin wants to know if HD audio is like HD video as far as clarity and resolution. He thinks that with cheap headphones, nobody is really going to tell the difference. So is it worth it? Leo says that David Pogue stated that HD audio is 'snake oil,' and it takes some training to hear the differences.
Mike wants to know the highest quality sound he can play on his iPod. Leo says at 320kbps AAC, but they also support AIFF and ALAC. ALAC is the highest quality he can get. But he'll want to be sure to rip the CDs uncompressed so he can start with the absolute best option.
Ted wants to listen to his music via Airplay, but he doesn't like that it's compressed. Leo says yes, music streamed over Wi-Fi will be compressed. So it's best to keep it all wired as a result. Since Ted has such great speakers, he'll want to get a digital to analog converter to play the music through his computer. He should rip his CDs using Apple lossless or FLAC. FIIO is a good company for DACs.
Pete is interested in hi-res music. He wants to download FLAC music and convert it to Apple lossless. Leo says you can do that, but remember that the MAC tops out at 96 Khz, but the iPod can't play it because it's not that high, nor does it have the CPU power to process and playback hi-resolution audio. You need special hardware to play back high resolution audio. Leo says that iPods were designed for mp3s, but they can play back Apple's lossless compression at 48K x 24 bit.