Music Please, unbeaten in three starts as a 3-year-old last year while racing exclusively at seven furlongs, tries to run a bit farther and significantly faster than she has ever run before in Saturday’s $75,000 Nellie Morse Stakes at Laurel Park. The one-mile Nellie Morse drew a field of six fillies and mares, includiing stakes winner Baltimore Belle and graded-stakes-placed New York shipper McVictory. Music Please, trained by Rodney Jenkins, has steadily improved her Beyer Speed Figures from a 54 in her career debut in October, to 62 in a first-level allowance win in mid-November, topped by a 67 for her off-the-pace three-quarter-length victory in last month’s Squan Song for Maryland-breds. Although Jenkins shows a good 6-for-29 record (21 percent) with horses moving from sprints to routes after a break of 31 to 60 days, Music Please is significantly slower on the Beyer scale than either Baltimore Belle or McVictory. The 4-year-old Baltimore Belle will be making her first start since moving into the barn of Mike Trombetta. Formerly with trainer J.B. Secor, Baltimore Bell, a daughter of Bowman’s Band, was purchased by Larry Johnson for $130,000 at the Fasig-Tipton Midlantic December Mixed Sale at Timonium and sent to trainerTrombetta. She has posted five workouts in anticipation of this start, including three bullet performances.   “She is all class,” said Tana Aubrey-Verge, Trombetta’s assistant. “She couldn’t be doing any better. She is training well and is happy in her new home. J.B. told me that I would love her and he was right.” In her two most recent starts, both going the same one-turn mile as Saturday’s race, Baltimore Belle won the Maryland Million Oaks and was second in the Twixt while recording Beyers of 81 and 85. McVictory, third in the Grade 3 Bed o’ Roses last July and second with a career-best 90 Beyer in the Justakiss at Delaware Park in November, will be coming back just six days after finishing third with an 85 Beyer in an overnight stakes at Aqueduct. It’s difficult to assess how McVictory will perform on short rest. Her trainer, Todd Pletcher, has not started a single horse twice within seven days in the past five years, according to DRF ’s Formulator. Among the others, the most intriguing upset possibilities are recent maiden winner Heavenly Choir and Potosina, who was good enough as a 2-year-old to win a turf stakes in New York and run in the Breeders’ Cup Juvenile Fillies Turf. Heavenly Choir returns 15 days after romping by eight lengths in her seventh try against maidens. Potosina endured rough starts in her last two races, both in New York. Three races back, when she got a clean break and was able to show high early speed, Potosina won by daylight in a second-level allowance at Parx Racing.