sentiment_words <- tidy_df %>%
  inner_join(get_sentiments("bing")) %>%
  count(genre, word, sentiment, sort = TRUE) %>%
  ungroup()

sentiment_words %>%
  group_by(genre, sentiment) %>%
  top_n(5) %>%
  ungroup() %>%
  mutate(word = reorder(word, n)) %>%
  ggplot(aes(word, n, fill = sentiment)) +
  geom_col(show.legend = FALSE) +
  facet_wrap(~genre, scales = "free_y") +
  labs(y = "Contribution to sentiment",
       x = NULL) +
  coord_flip() +
  ggtitle('Figure 6: Words contributing to sentiments per genre')