Are the lead sheets (tabs) important each week?
The most important things to focus on in each week are (in the following order):
1. Focusing on mastering the scale shapes for each week.
2. Playing the lead sheet for the given week.
Let me expand on this a little more:
Mastering all of the scale charts should be the main goal each week. These are the foundations of music and need to be memorized for any and all lead playing, regardless of the style you seek to develop. Players who don't know their scales and who are not able to play in multiple keys severely limit their musical growth. The primary focus of Shred-Machine besides building technique is to teach mastery of the fretboard.
The lead sheet takes examples from the scales for each week and includes other things such as arpeggios that are frequently a part or shredding. Using the lead sheet (especially during the first few weeks) will introduce your fingers to these new concepts and will get them programmed into your muscle memory. In the future, when you jam or write your own solos, you will be able to play these licks easily.
In the subsequent weeks of Shred-Machine, you will find that these lead sheets will become more difficult to play as the tempo will be faster. As a result, the lead sheets are listed as optional in the weekly instructions (they are not required for you to do that week).
Let me know if you have any more questions,