In order to have a first visualization of which was the sentimental analysis behind Beatles lyrics, it seems a good idea to see how the average mood evolves by year. Thus, a scatter plot is aimed, where the x-axis corresponded to the year and the y-axis to the mean labMT value per song. Moreover, each each writer will be represented with a specific color. Only songs that are in the Giant Connected Component and in the Beatles Golden decade (1962-1970) have been included.

As aimed in the scope we want to include the Sentimental Analysis according to both LabMT and VADER criteria. In order to achieve so, below we have first defined a function that computes the average LabMT value per song. To achieve so, first the labMIT.csv is imported and the average happiness score for each word is saved in a dictionary. Then a function is defined in which the song (input) is read from lyrics songs folder and cleaned by applying clean_lyrics() function. Then the average score for each word of the cleaned file is stored and the mean is computed and returned.

It can be seen how there is not a clear tendency in the general mood of Beatles songs as years pass by, mainly following a distribution around 5.5 and 6 average LabMT values.

However, it seems that Beatles songs tend to slightly increase its positivity as years go by. After their first hit "Love Me Do" in late 1962, Beatles popularity started to increase in insane levels. By early 1964 they were already international starts and had achieved unprecedented levels of commercial success. Who knows if this increases success was the main cause behind this slow increase in positivity by years.

Nonetheless its maximum average value is reached at year 1968. From there, their average positivity starts to decrease the last two years of this golden decade, before their break-up at 1970.

However, maybe an analysis with VADER makes more sense, due to the mood of the songs usually resides in how the sentence is written and not just in single words. So same procedure has been done but now computing the average sentimental value of each song according to VADER criteria. Due to a lot of neutral sentences were observed, two different graphs have been made. First one, considering all song sentences (more robust) and second one just considering these sentences that differ from neutral mood. These are the results obtained:

It still can be observed how the positivity of Beatles slightly decrease during the first years of the decade, reaching an average VADER value of 0.2 between 1965-1966. From there, VADER average values slightly increases reaching a maximum around 1968-1969 before doing a significant decrease on 1970, the year of their break-up.

Although LabMT and VADER graphs differ when showing the sentimental analysis of Beatles songs by year, there is a thing that can be observed in both graphs, and it is this significant decrease in positivity in last year. Of course it is true that is not enough at all to affirm that, but this gives space for our imagination. Is this increase in negativity related with the fact that their break-up was just around the corner? Could the break-up of the Beatles have been predicted and therefore tried to be avoided if sentimental analysis had been implemented and this decrease in positivity had been detected before it was too late?

Known was the most used word in Beatles song, appearing in 44% of their total releases. Thus, it seems interesting to filter these songs and perform a Sentimental Analysis on them. If we take a look at how the songs containing "know" evolve, we see how their is a small tendency to decrease, although its behavior is rollercoaster. What seems clear is that 1965 is one of the more negative years with respect to songs including the word "know". As a curious fact, this year album "Help!" and "Rubber Soul" were released. Hits such as "In My Life" belong to this year. John Lennon described it as “a remembrance of friends and lovers of the past.” Thus, makes sense that this year is one of the most saddest ones.

With respect to the evolution of "love" word, also mainly used by Beatles and appearing at 40% of their songs, some compelling conclusions can be extracted. First, that at least in the LabMT the perspective of love seems to be more positive as years go by. Specially, from 1965 until 1970. Although, their general positivity decreases during the last years, it seems that they decided to keep some space for optimism when it comes to love. Hits such as "Something" belong to this category, which shouldn't surprise us considering that is one of the most wonderful love songs, were Harrison asks himself if he could possibly love her lover more than he already does. What seems clear is that she has "Something in the way she moves that attracts him like no other lovers". Secondly, it can also be observed how there is a huge density of songs containing the word love in the first years, and go years go by their frequency decreases.

Word "see" is used in 33% of Beatles songs. From the graphs above it seems that its tendency follows the same one as the seen with "love" word, as years go by, it positivity increases. Is your "love" perspective also related with how you "see" the things?

We can find the word "see" in songs such as Come Together and Let It Be, both released at the end of the decade. Thus, is anyone surprised that speaking words of wisdom is related with an increase of positivity?

However, although everyone has listened at least once this song, not everyone knows the meaning behind it. According to McCartney words:

"Let It Be" happened during a time when there was kind of a lot going on," McCartney said. "I think people were overdoing the use of substances. We certainly were. But I had a dream where my mother, who had been dead at that point for about 10 years, came to me in the dream and it was as if she could see that I was troubled. And she sort of said to me, she said, 'Let it be.' And I remember quite clearly her saying ,'Let it be,' and 'It's going to be OK. Don't worry.' You know, 'Let it be.'

With respect to word "time", it is present in 30% of Beatles songs. Here an exciting thing can be observed. Apart from the rollercoaster behavior, two main peaks are clearly present in 1964 and 1968, reaching average LabMT levels of around 6, and VADER levels above 0.2. Why this drastic changes in the "time" word perspective?

With respect to 1964, the song with highest LabMT average value is I Feel Fine, written by Lennon. In 1968, it correspond to Birthday song, written by Lennon and McCartney. There is not a clear explanation of why songs contemplating "time" have such significant changes perspectives. But the true is that, whereas exists an explanation behind or not, results are there.

As a curious fact that might have some impact behind, on August 29, of year 1966, Beatles arrived in San Francisco to wrap up their summer tour with a show at Candlestick Park. But what might at first have seemed like an unexceptional event actually signaled the end of an era, as they had all agreed this would be their final concert.

Moreover, in the early August of 1966, Christian groups, primarily in the Southern United States took to the streets to burn the sin out of their beloved Beatles records in response to John Lennon's remark that the Beatles were “more popular than Jesus.”

All these are just facts that happened during 1966, curiously enough, one of their most negative years with respect to "time". Being these just mere coincidences, what is true is that what a "time" to be alive.