Can a Bard use Prestidigitation to conjure a musical instrument trinket for their spellcasting focus?

Question

Per the spell description for Prestidigitation (page 267 5e PHB),

... Components: V,S ... You create a nonmagical trinket ... that can fit in your hand and that lasts until the end of your next turn.

Per Spellcasting Focus for Bard (page 53 5e PHB),

You can use a musical instrument (see chapter 5, "Equipment") as a spellcasting focus for your bard spells.

Per the Musical Instruments section of the Tools section (page 154 5e PHB),

Bagpipes, Drum, Dulcimer, Flute, Lute, Lyre, Horn, Pan Flute, Shawm, Viol

The Material section of Components (page 203 5e PHB) does not make any reference to conjured items not being used as a spellcasting focus.

Relevant Trinkets (page 160-161 5e PHB)

A tiny gnome-crafted music box that plays a song you dimly remember from your childhood ... A tiny silver bell without a clapper ... A metal can that has no opening but sounds as if it is filled with liquid, sand, spiders, or broken glass (your choice) ... A whistle made from gold-colored wood ... A set of bone pipes

From these trinkets, we can see that they are able to make music (music box, whistle, possibly bone pipes). The metal can could be used as a ganza (a type of rattle/percussion instrument).

The last bit of evidence that I can see for this being a "legal" ability is the specification in the spell description of Creation (page 229 5e PHB)

... Using any material created by this spell as another spell's material component causes that spell to fail.

This condition is not present in Prestidigitation or any other Bard-relevant spellcasting focus description.

Also, I realize that "ask your DM" is the obvious thing to do in situations like this, but I'm more interested in a literal interpretation of the rules.

Answer 1

Yes, it can

You can make any non-magical trinket that can fit in your hand, and it disappears after the end of your next turn. One of the trinkets you can make, as listed under PHB 160, is "a whistle made from gold-colored wood" as well as "a tiny silver bell without a clapper"; these are both things that you could make such that they can fit in your hand.

Furthermore, they fit the criteria of "musical instruments," because you can make music with these. While the PHB does list some of the things it considers as instruments, it is not meant to be an exhaustive list:

Tools, PHB 154

Musical Instrument. Several of the most common types of musical instruments are shown on the table as examples.

This means prestidigitation can create a musical instrument that can fit in your hand, and you can use any musical instrument as a spellcasting focus.

Of course, it is inefficient

You must use your action to cast prestidigitation, and then you cannot use your action again to cast another spell. On your next turn, you could use the instrument to cast a spell, but then it disappears at the end of that turn, and you have to recreate it on your third turn. This allows you one spell every other round that isn't prestidigitation (unless it's a bonus action or reaction spell).