Sound Within Sound by Kate Molleson review – a challenge to the gatekeepers of classical music

When Radio 3 presenter and critic Kate Molleson was a child, she would take her Fisher-Price tape machine to bed, clutching it like a cuddly toy, falling asleep to Monteverdi madrigals. Her love of Bach, Beethoven, Vivaldi and Tchaikovsky followed soon after; then her interests moved to ambitious modern composers, many of whom were not western, male, white or in any history books.

In this clever and accessible collection of essays, Molleson lays out her case for 10 of these artists, saying their work is still sidelined because of an “odd and spurious fear”: that inclusivity threatens classical music. “Nobody is mooting that we should ditch Mozart or Mahler,” goes her powerful preface. “I would be the first to fight back if anyone did.” Instead, she questions the “gate-keeping and wall-building” within classical music and how matters of gender, country of birth and class affect ideas of how certain composers have been, and continue to be, appraised.

Classical music, she argues, desperately needs diversity to survive: “Stagnation will be the death of any living art form… healthy musical culture depends on who’s playing, who’s listening, who’s genuinely impacted.” To help this mission along, Sound Within Sound takes us on a whirlwind international tour.

It introduces us to thrilling dreamers from the last century who believed that music could fundamentally – and disruptively – recalibrate our lives. In Mexico, we meet Julián Carrillo, the youngest of an indigenous family of 19, who becomes a composer obsessed with the possibilities of microscopic intervals between tones (in layperson’s terms, the many tiny gradations of sound between two notes on a keyboard).

Music using such microtones could create a mystical realm that would unlock people’s minds, Carrillo believed, to “access fresh responses that were visceral, unfiltered, futuristic”. Filipino composer José Maceda has another dream in the 1960s: of a composition involving thousands of cars, blasting out different parts while they cruise around on motorways, creating a participatory musical experience.

It never happens, but an hour-long piece Maceda writes in 1973, Ugnayan, for 20 radio stations, does get performed, played by transistor radios all over the country in homes, public places and parks, people moving around with their portable machines to make the sounds mesh and mingle.

These stories could get easily bogged down in musical jargon, but Molleson’s enthusiastic style and eye for character and place give them life. The international sweep of her book is especially compelling when she is travelling: when she is in “dusty, nervy, loud” Jerusalem to meet the 93-year-old bed-bound Ethiopian pianist and former nun, Emahoy Tsegué-Maryam Guèbrou, or among the “yellows and fierce golds” of the birthplace (St Petersburg) of Molleson’s refugee grandfather as she explores the brutal dissonance of Russian composer Galina Ustvolskaya.

Many of these artists emerge as compelling, almost cinematic characters. Walter Smetak, an influence on Brazilian pop music in the 1960s, is a “taciturn, craggily handsome buckaroo of Bahia”. At one of the American free-jazz composer Muhal Richard Abrams’s last gigs, Molleson captures his physicality in energetic, propulsive sentences. “He lingers in the bottom octave then erupts upward. His fingers clamber around the keyboard as though speed-scaling a cliff face.”

Injustice plays a part in many tales, including the life of Ruth Crawford Seeger, mother of the acclaimed folk musician and singer-songwriter Peggy, with whom Molleson spends a fascinating, revelatory day. The first woman to be awarded a Guggenheim fellowship for her work and an innovative modernist composer, Crawford Seeger’s talents were constantly disregarded by her husband, who was formerly her teacher. “He wasn’t nearly as good as she was,” Peggy says, bluntly.

We see a letter Crawford Seeger sent to her brother in 1945: “all during the house-cleaning I was thinking of the books I might be working on”, she writes. She became an internationally respected transcriber and arranger of traditional songs, but didn’t write another modernist piece until 1952; she died a year later of cancer.

Sound Within Sound makes us realise that there was so much more music out there by people like her, plus music that was never finished, written down or performed. It also focuses our ears on the brilliant stuff that survives, encouraging us to dig deeper and keep listening.

• Sound Within Sound: Opening Our Ears to the 20th Century by Kate Molleson is published by Faber (£18.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply