The lead-in is noted material occurring before the first completed bar and is also called a pick up.
Example 80 involves the use of a lead-in (or pick-up) note which is played before the first bar of music on the count of "4 +".
Example 81 starts with two lead-in notes on the 4th beat.
Example 82 has three lead-in notes starting on the "3 +".
Eighth note triplets are a group of three evenly spaced notes played within one beat. Eighth note triplets are indicated by three eighth notes grouped together by the numeral 3. Each part of the triplet is worth a third of a beat. Triplets are easy to understand once you have heard them played.
Example 84 uses triplets as demonstrated in the last example.
Example 85 alternates between triplets and quarter notes in octaves which is a very common interval for Funk Bass lines. The first bar starts on a triplet with low Cs followed by the quarter note high C.