It’s not about being smart, it’s about being alive

Rogers and Hammerstein changed Broadway. They took it forward by making it less a geographical location where hits were born, and more a standalone genre with new rules and regulations. With their exotic but defiantly non-metropolitan locations, they also took it back to a time when the book drove the songs, back to the time of light opera and operetta. … Certainly, ‘Oh, What a Beautiful Mornin’’ didn’t have the urban smarts of Rogers and Hart, but as Sondheim himself later responded, ‘It’s not about being smart, it’s about being alive.’

B. Stanley, Let's do it: the birth of pop (2022), 436

This was a high water mark for musical theatre – for great American songwriting, even

In 1927, within a few blocks of Showboat you could have also seen George and Ira Gershwin’s Funny Face, Vincent Youman’s Hit the Deck or Rogers and Hart’s A Connecticut Yankee. This was a high water mark for musical theatre – for great American songwriting, even – but then two things come along to spoil the fun: the Wall Street Crash and talking pictures. In 1928 there were sixty-two shows along Broadway; this would decline to thirty-four in 1931. During the whole of the 1930s, the Great White Way would  host only sixty-eight new musical comedies.

With a very real lack of cash and opportunity for the New York songwriter, the lure of Hollywood – just about the only place in 1930s America where there seemed to be a silver lining – would prove irresistible.

B. Stanley, Let's do it: the birth of pop (2022), 110

At least there was no danger of them being exposed to anything dangerous, like an idea

Cats was also that increasing rarity, a musical that one could take children to. The tykes might die from vapidity poisoning, but at least there was no danger of them being exposed to anything dangerous, like an idea.

J. Kenrick, Musical theatre: a history (2008), 348

Evita left history to its own devices and made gobs of money

Both Sweeney and Evita were expensive productions with stunning stage direction by Harold Prince. Both won seven Tony awards, including Best Musical, in adjoining seasons. The key difference: Sweeney Todd made theatrical history but lost money, while Evita left history to its own devices and made gobs of money. This was not lost on producers and investors. It is easy to advocate artistic merit over financial concerns, but answer this: if you were investing $100,000 or more of your own money.

J. Kenrick, Musical theatre: a history (2008), 341

If you thought I was describing another show, that's understandable

The big opening chorus number had been a staple in musical theatre since Offenbach's time, with a huge chorus (preferably of females) there to grab the audience's attention. So the opening night regulars were caught off guard when a new Broadway musical began with a lone woman on stage in the middle of a busy morning. Moments later, a man came on to sing the opening number as a sole, with no ensemble in sight. The effect was fresh and charming, as was the heroine's dream ballet, where she got to choose between two suitors. No wonder Louisiana Purchase (1940, 444 performances) was a hit.

If you thought I was describing another show, that's understandable. Misinformed sources have suggested that Oklahoma! invented such features as a two-opening, a dream ballet, and (most laughably) the integration of song, dance, and dialogue. There is no question that Oklahoma! was a landmark work... but many of the seemingly "new" things in it had been brewing on Broadway for some time.

J. Kenrick, Musical theatre: a history (2008), 238 

You know how dis ends. The horse, he wins the race, and the boy gets de girl. Now, you wanna see that, or you wanna hear Jolson sing?

In the delightful memoir All my friends (Putnam, 1989), George Burns explains how Jolson would stop a musical midscene and in Gus's pseudosouthern drawl say: "You know how dis ends. The horse, he wins the race, and the boy gets de girl. Now, you wanna see that, or you wanna hear Jolson sing?" He then sent the cast home and offered a prolonged selection of his hit songs.

J. Kenrick, Musical theatre: a history (2008), 159

The soundtrack of the American musical South Pacific spent forty-six weeks at number one

The most popular Beatles' album, Please Please Me, spent forty-three weeks in the Top Ten. By comparison, the soundtrack of the American musical South Pacific spent forty-six weeks at number one, and more than three years in the Top Ten. Yet even this was dwarfed by the outstanding musical product of the sixties, Rogers and Hammerstein's The Sound of Music. The two versions of this phenomenally successful musical - a Broadway recording from 1960 and the film soundtrack of 1965 - remained in the Top Ten of the album chart for more than five years, and the film soundtrack held the number one spot for a staggering 69 weeks.

D. Sandbrook, White Heat (2006), 412-3

Musicals are for the sorts of people who, even though their coach will be awaiting outside the theatre after the show, take their umbrellas

Musicals are for people who are too thick for opera and too square for pop music. They are for people from the sticks, who migrate en masse  to the major capitals of the world where they enjoy themselves by watching things they have seen before at twice the price they paid last time. Musicals are for the sorts of people who, even though their coach will be awaiting outside the theatre after the show, take their umbrellas.

E. Brockes, What would Babra do? (2008), 45

[Note: this is neither my view, nor that of the author. I love musicals, I just thought this was a brilliant a summary of the (unfair) contempt in which they are held]