At some point I will write up Garcia's engagements with reggae. It's an interesting story, really revelatory.
In the meantime, on a lark, I played with Google Ngram for these two. Ngrams are a very neat tool.
Figure xxx. Google Bigram: Bob Marley and Jerry Garcia, 1965-1981
The vertical is the percentage of all consecutive two-word phrases in English language books from the given year, digitized by Google (all of them, pretty much, by the 1970s), comprised by the respect phrases "Jerry Garcia" and "Bob Marley".
This metric is good to compare over time appearance of the phrase (of N components, hence Ngram) (look at the sharp Marley trajectory to his passing, and Garcia's relative stability to this point). Hypothesis: "Grateful Dead" will reveal this same kind of trend as Garcia; both will spike up 1986ff.
But it's also good to compare cross-sectionally, i.e., Garcia and Marley. Very simply, the picture says that Garcia was more popular earlier in this series, their stardom paths crossed in 1973, and Marley soared to greater fame until his death, while Garcia's level was established around 1973 and stayed steady during the rest of the period to 1981.