Instead of studying at Tempe, he went off to the University of Arizona in Tucson to continue studying music with Madame Elenore Altman, a pianist from Poland, who had begun tutoring him as a child. He played football for the university.
"Madame Altman was always telling David to quit the football team down there," his sister Rachael, now 90, recalls, "because he was constantly injuring his hands. But every Saturday she'd be there in the stands, rooting him on."
Back in Phoenix in the late 1930s, with a master's degree in music, Murdock taught music at Glendale and Tolleson high schools, directed choirs and led the Orpheus Club, a local men's choral society.
In those days before the war, says Rachael, Murdock would sometimes wander the strip of desert that the Ellises had on Cattle Track in Scottsdale, playing what he called "growing tunes" on a flute. Like millions of others in the civilian army, fighting a war was about the last thing he wanted to do.
When he was drafted into the Army on August 11, 1941, he hoped that his musical experience would land him a spot in the Army band. But he wound up in basic training at Camp Wolters, Texas.
Midway through the training, he wrote to his mother in Washington that he didn't mind the miles and miles of maneuvers "thru brush and hills and sand. No gripe, I can take it as well as any and better than most, but it all seems so pointless, a muddled up mess & no [one] knew where we were going nor what they were supposed to do . . .
"I wouldn't give a dime for our chances against an organized enemy, yet the Generals in the critique this morning say we 'did a fine job' and I ask, What job? I never did see a job to be done. And we're supposed to be the best division in the country. O Boy. . . ."
Murdock's sister recalls that boot camp was a real jolt to her brother's independent and opinionated nature. "Once he saw what that was about, he knew the only possibility for him was to go for officers training."
He applied for officers training and got lieutenant's stripes the following spring, at Fort Benning, Georgia. He was graduated near the top of his class.
That summer, he joined the Army's 3rd Division, 7th Infantry Regiment at Fort Ord, California, as commander of an infantry platoon.
Along with millions of other soldiers and their families, the Murdocks spent the late summer and early fall of 1942 wondering where the Army would send him. His brother, Ben, was already working in the Army's Signal Corps as a radar specialist watching the waters off the end of Long Island.
At the time, there was considerable speculation about where Americans would land to begin their attack on Europe. A likely target was North Africa, along the Mediterranean, where the British were fighting German forces in the deserts of Libya, Egypt and Tunisia.
David Murdock's regiment maneuvered in coastal mountains around Fort Ord, where the terrain and climate were similar to parts of North Africa. At one point, he was given a desk job at the regimental headquarters. But it was a temporary post.
The silence about where he might eventually wind up fed feelings of isolation and helplessness among his family at home.
"Gosh, it seems ages since anyone has written," Rachael wrote to her parents that fall. "I've almost decided the whole family has been shipped out.
"It gets harder and harder for me to figure things out or realize what's going on, you know sitting out here on the desert day after day with nary a change for years. I get all balled up thinking about the war, where it is, David and Ben, where they are, war policies in Washington etc. I'm just not in the picture somehow."
Her husband, George Ellis, was the civil engineer at Williams Field. He left every morning at 6:20 to start the 40-mile drive from Scottsdale. He returned exhausted after 5 each evening.
"He's going to have three passengers after this week," Rachael went on, "and that will help since it costs him $1.50 per day now to go and come. I think when they get the laboratory set up he'll take a cot over and stay over night part of the time. There are so many things to do here -- and he's too tired to do much -- and he only has Sundays off . . .
"I think mostly about David and Ben these days. I know you do too. I'm thankful they are both strong -- mentally and physically -- and hope to heaven they're lucky. They're super guys and I just can't think that fate would let them down. . . . Wish we could all ship out with the 3rd Division and help look after him, don't you?"