When he died in 1869, Louis Moreau Gottschalk was the most famous musician in the Western Hemisphere. New Orleans’s answer to Europe’s great virtuosi – the Chopin of the Creoles, as he was called – Gottschalk enjoyed the kind of popularity that today we associate with rock stars. In the smallest towns of the American West, on isolated Caribbean plantations, in war-torn Latin American capitals, listeners turned out by the hundreds and thousands to hear him. Girls passed him notes before concerts, begging him to play their favorite pieces. He gave command performances for President Lincoln and the emperor of Brazil. His compositions, short and sparkling piano pieces that drew heavily on folk rhythms and popular tunes, sold tens of thousands of copies. During the Civil War, his patriotic fantasia “The Union” and his sentimental “meditation,” “The Dying Poet,” were some of the best-known pieces of music in America.

A century and a half later, Gottschalk’s name has faded to a historical footnote. But his music can still be heard, on record if seldom in the concert hall; and while no modern listener would mistake him for Chopin, he deserves an honorable place in the American musical tradition. His best compositions are a surprising blend of African-American and Latin rhythms with elegant salon pianism. Pieces like “Le bananier (Chanson negre)” or “La savane (Ballade creole)” can be seen as early attempts at a fusion of European and African musical traditions that would come to define American popular music.

Indeed, Gottschalk himself was a prime example of American hybridity. His father was an English Jew, his mother the descendant of French planters who fled Haiti after the rebellion of Toussaint L’Ouverture. Their paths crossed in New Orleans, where Gottschalk was born in 1829, and where he absorbed Creole music in his cradle. At 13 he was sent to Paris to complete his musical education and met Berlioz, Chopin, and other titans of the day. He made his concert debut in Paris in 1849, and for the next four years toured triumphantly around Western Europe.

Armed with the cultural imprimatur of the Old World, Gottschalk returned to his native country in 1853, hoping to repeat the success of Jenny Lind’s famous American tour. While Gottschalk eventually reached those heights, it proved to be a long, arduous road. Exactly what it took to become a musical superstar in the mid-19th century is vividly documented in “Notes of a Pianist” (Princeton University Press, 433 pages, $24.95), Gottschalk’s charming and fascinating diaries, which are now back in print for the first time in decades.

Covering the years 1857 to 1868, Gottschalk’s journal shows the pianist as a one-man Grateful Dead, his whole life a long, strange trip. We see him travel to Montreal from Cuba, to Lima from New York, playing a concert every day, sometimes twice a day. “I have given eighty-five concerts in four months and a half,” Gottschalk wrote at the end of 1862.

I have traveled fifteen thousand miles by train. … A few more weeks in this way and I would have become an idiot! Eighteen hours a day on the railroad! Arrive at seven o’clock in the evening, eat with all speed, appear at eight o’clock before the public. The last note finished, rush quickly for my luggage, and en route until next day, always the same thing! … The sight of a piano sets my hair on end like the victim in the presence of the wheel on which he is about to be tortured.

If Gottschalk were always so peevish, “Notes of a Pianist” would make for dull reading. Fortunately, he treated his diary (which he kept in French) as an antidote to the tedium of life on the road, filling it with sharp observations about people, places, and music. The diary’s first section covers Gottschalk’s tours of the Caribbean in 1857-62, and the last section finds him in Latin America from 1865 until his death, from yellow fever, four years later. But it is the middle section, written during his nonstop tours of the United States, that are most fascinating to an American reader. Gottschalk’s upbringing, at the intersection of American, French, and Caribbean influences, made him an ideal observer of his young country, an insider and an outsider at once.

“Notes of a Pianist,” in fact, is one of the most vivid and unvarnished records of ordinary life in the North during the Civil War. (Gottschalk, though born in Louisiana, was a committed opponent of slavery, and he swore allegiance to the Union.) This was 19th-century America as an itinerant musician saw it: railroad cars full of drunk, swearing soldiers; hotel clerks looking down their noses as they overcharged for terrible food; concerts held in courtrooms, or in newly built halls with dangerously sloping stages. Music, Gottschalk makes clear, was not an easy way to make a living. To make a victorious tour of concerts in the West,” he wrote in Bloomington, Ill., is for an artist to gain his chevrons. Bad hotels, snow, mud, railroad accidents, delays, setting out at three o’clock in the morning, etc. … I am tempted to have inscribed at the head of my program: ‘G. has made the tour of the West three times,’ as the French legions inscribe ‘Arcole, Marengo, Austerlitz’ on their standards.

But “Notes of a Pianist” is informative, above all, as a document of our cultural adolescence, a time when Americans knew they were supposed to want good music, but weren’t quite sure how to enjoy it. Often Gottschalk is bemused by his listeners’ sheer ignorance. In one small town, a woman in the audience laughs at the movement of his feet – she had never seen a piano with pedals, and thought he was doing a little dance. In another, a farmer points at the piano and asks him “what that big accordion was.” For such people, Gottschalk’s concerts, with their $1 ticket price, were an intimidating, highbrow alternative to minstrel shows.

On the other hand, the self-appointed guardians of musical taste, especially German immigrants and Boston Brahmins, looked down on Gottschalk as a purveyor of tawdry novelties. He almost never played Mozart or Beethoven (whose piano music, he writes, “falls below mediocrity – the least pianist of any intelligence, in our days, writes infinitely better than Beethoven ever did”). Instead, he pleased the crowd with fantasias on themes from Meyerbeer and Verdi, sometimes played by 10 pianos at a time in “monster” concerts. When he was sniffed at by someone like John Sullivan Dwight, the editor of Dwight’s Journal of Music, the normally amiable Gottschalk could become enraged: “Dwight’s paper is the reservoir of every little bilious envy, of every irritating impertinence, of all sickly spleen.”

Gottschalk’s position was a thankless one. On the one hand, he faced listeners like the wife of a St. Louis judge, who told him that his music was “too learned,” that he should simply play “Hail Columbia” and “Yankee Doodle.” On the other, there were critics like Dwight, who wanted to see America develop first-class symphony orchestras that could play serious classical music. This fissure in American musical taste has never really been closed (our best native forms, jazz and the Broadway musical, have grown up inside it), but Gottschalk deserves to be remembered as one of the first musicians to try to bridge the gap. “We should all, however narrow may be our sphere of action, bear our part in the progressive movement of civilization,” he wrote with admirable Victorian earnestness, “and I cannot help feeling a pride in having contributed within the modest limits of my powers in extending through our country the knowledge of music.”