It’s called Power Tab Editor, and it’s free. Designed primarily for transcribing music in tablature (with standard music notation above), Power Tab Editor is also very useful for figuring out songs with fast, complicated parts.
Here’s how it works: Download and install the Editor. Then go to Power Tab Archive and search for a song you want to learn. All songs are submitted by everyday guitar fanatics like you and me, but because it takes a certain amount of musical knowledge to write anything resembling music on the Editor, the quality of the submissions tends to be much higher than the kind of stuff you find from a “Blink 182 Guitar Tabs” Google search.
The Editor has controls similar to a music player. Hit the Play button and your computer will play the song using MIDI, illuminating each note or chord as it’s played. Some (OK, all) the charm of the song is lost in the translation to MIDI, but at least you can hear how it’s supposed to be played. For those of us who learn best by ear, Power Tab Editor is invaluable.
Here’s a trick: If the song’s too fast, click the first part of the tablature, go up to “Music Symbols,” and choose “Tempo Marker”. Play with the BPM (beats per minute) until you’ve slowed things down enough.
Also, for those of you who teach or compose guitar music, Power Tab produces a lovely manuscript that you can print or save as a .pdf file. For example, here’s my transcription the guitar solo in The Postal Service’s song “Such Great Heights”:
Whether you’re transcribing your latest masterpiece, or just trying to learn Ashlee Simpson’s “Pieces of Me,” you’ll be happy with Power Tab. Ohmygod, I think I’m going to, like, go work on that one now!