Complex sentence: She previously played the Stradivarius "Wilhelmj" violin (1725), which was on loan to her from the Nippon Music Foundationand the Stradivarius "Ex Baron Feilitzsch" violin (1734), which was loaned to her from Gidon Kremer.
Split into simpler sentences: She previously played the Stradivarius "Wilhelmj" violin (1725), which was on loan to her from the Nippon Music Foundation. She now plays the Stradivarius "Ex Baron Feilitzsch" violin (1734), which is on loan to her from Gidon Kremer.