In a 1957 listing of Curtis recitals and events, Dalley is noted as first viola player in the production of Giacomo Puccini's opera Gianni Schicchi.
After graduation from Curtis, Dalley joined the faculty at the Oberlin Conservatory in Ohio and played second violin in the resident string quartet, while performing regularly in recital and as soloist with orchestra.
Eventually he moved to New York City where he free-lanced, then joined the short-lived American String Quartet with the cellist David Soyer.
"During his formative years, his father held a number of positions in different parts of the country, exposing the young violinist to many musical influences.
As a teenager, he participated as a violinist in the annual all-state school musical competitions for youth orchestras, bands and choral groups under the direction of Dr. Joseph E. Maddy.
Later, Howard Halgedahl, a world class bassoon player, directed the high school music program in Winfield.
Howard Taubman stated in the New York Times, "Do we, in the East, realize that the town of Winfield, Kansas, population 12,500, has one of the most admirable high school orchestras in nation?".
[3] Dalley held teaching positions at the Curtis Institute of Music in Philadelphia, and was artist-in-residence at the University of Illinois at Urbana-Champaign.
The Guarneri Quartet has taught, in various combinations at Rutgers State University of New Jersey and the Manhattan School of Music.
In summer 1958, the quartet won a bronze medal in the Concours International de Quatuor sponsored by H.M. Queen Elizabeth Music Competition in Liege, Belgium.
Soyer chose as his replacement his former cello student Peter Wiley, also a Curtis graduate, who had for many years been the cellist with the Beaux Arts Trio.
Although the four performed together in concert, and they practiced together for three hours a day, "on tour the members travelled independently, and booked hotel rooms on separate floors.
"[15] Two other rules were 1) No wives were allowed to be involved with the quartet business, and 2) The inner dynamics of the rehearsing and concert venues made it a compliment-free zone between the four.
Although much less rare than the Stradivarii, the specific venerable instruments owned and played by the quartet's members, with their craftsmanship, type of wood, varnish, and all of substantial age, together "created such a warmth and complexity of sound that enticed, then seduced each of us.
Arnold Steinhardt said at the end of the quartet's forty-five year run, "This is an extraordinarily difficult task before us, to realize the masterpieces in our repertoire to any satisfaction.
Later the group spent almost two seasons playing nothing but piano quartets with Dalley in the violin seat while Steinhardt recovered from surgery on his arm.
These performances have taken him to Canada, Mexico, South America, Europe, Israel, Australia, New Zealand, Japan and other parts of Asia, and widely throughout the United States.
He has performed in famous concert halls throughout the world, in venerable old music schools, high school and college auditoriums, and many other places, such as the informal beach house at Half Moon Bay in Northern California where, in November 1964, he was a featured performer at one of the San Francisco Bay Area's much loved, but quirky Bach Dancing and Dynamite Society.
In a sales catalogue, one of his violin bows is described as having an "exquisitely crafted Brazilian pernambuco shaft, elegant silk wrapping and a diamond-shaped inlaid frog".
"[20] Dalley brings his meticulous attention to detail and love of aesthetics to his bows that he has brought to his playing.
[20] Dalley's craft and skill produce violin bows that are in high demand because of their quality and rarity.
Among its other award-winning recordings are collaborations with such artists as Artur Rubinstein, Pinchas Zukerman and Boris Kroyt and Mischa Schneider of the Budapest Quartet.
[29] Dalley has made recordings with other notable artists, such as Leonard Rose, Artur Rubenstein, Pinchas Zukerman and members of the Budapest Quartet.
In summer 1990, the Guarneri Quartet members were interviewed by Charles Kuralt on CBS's nationwide television program, Sunday Morning.