No Budget Band sfz instruments.
https://nbo.libreorchestra.net/download/http://www.bandshed.net/sounds/sfz/(pianos -  Little Lizard Piano - dx7 - honkytonk - hpiano)
http://download.linuxaudio.org/musical-instrument-libraries/sfz/You can extract the instruments where you like and just drag the Instrument.sfz straight into Sforzando.
To add the Instruments to the PG Sforzando Library Menu,
open C:\Program Files\PG Music Inc\Band-in-a-Box Sounds\Band-in-a-Box Sounds.bank.xml in a text editor or 
https://notepad-plus-plus.org/and you instruments to the menu data (see example below). Create a backup first of Band-in-a-Box Sounds.bank.xml.bak
in Mac Library/Application Support/PG Music Inc/Band-in-a-Box Sounds/
Extract the to Win C:\Program Files\PG Music Inc\Band-in-a-Box Sounds\Programs\NoBudgetBand, in Mac Library/Application Support/PG Music Inc/Band-in-a-Box Sounds/Programs/NoBudgetBand
example:  Rickenbacker Bass added under	<!-- Bass -->
	<AriaProgram  name="Rickenbacker"   	gui="GUI/Generic.xml"> 					<AriaElement  path="Programs/NoBudgetBand/Bass/BrightRick/bright_rick.sfz"/> </AriaProgram>
You can edit the instruments to create your own key switched articulations  
See Here  BandOrgans    60s Organ
    Accordion
    B3
    Calliope
    Harmonica
    Rock Organ
    Tango Accordion
Guitars    Banjo
    Les Paul
    Les Paul 2
    Mandolin
    Nylon Guitar
    Steel String Guitar
    Fender Stratocaster
    Yamaha
Basses    Electric Pick
    Electric Twang
    Fender Finger
    Fender Pick
    Rickenbacker
    Synth Analog
    Synth Bright
    Synth Pluck
Synths    Harpsitar
    Mellowtron
    Obow
    PolySaw
    Synth Brass
    Synth Strings
    Tack Piano
Orchestra
Strings    Solo Violin
    Solo Violin 2
    Violin Section
    Solo Viola
    Solo Cello
    Cello Section
    Solo Double Bass
    Double Bass Section
    Harp
Woodwinds    Piccolo Section
    Solo Flute
    Flute Section
    Pan Flute
    Recorder
    Solo Clarinet
    Clarinet Section
    Solo Oboe
    Oboe Section
    Solo Bassoon
    Bassoon Section
Brass    Solo Trumpet
    Mute Trumpet
    Trumpet Section
    Solo French Horn
    French Horn Section
    Solo Trombone
    Trombone Section
    Solo Alto Sax
    Solo Tenor Sax
    Sax Section
    Solo Tuba
    Tuba Section
Harpsichord
Choir
Percussion Guitar All Guitar instruments are stereo.
Many of the guitars have different styles of playing (ie, articulations). For example, the LesPaul electric guitar has both sustained and muted notes, hammer on/off, harmonic, and some percussive effects. Each articulation is available in a separate sfz file. For example, the LesPaul has 4 sfz files named lp_sus.sfz, lp_mute.sfz, lp_harmonic.sfz, and lp_noises.sfz for the sustain, muted, harmonic, and percussive articulations, respectively. (The hammer on/off articulation is included in the sustain articulation).
Files with a short, nondescriptive name, usually a capital letter followed by a number such as S1, S2l, N1, etc, are not to be used directly. They're support files.
Often, you want to switch articulations for a given instrument. In order to switch articulations on-the-fly, you normally need to load the sfz file for each articulation, and set it to a different MIDI channel. When trying to play and switch articulations live, it can be inconvenient to deal with multiple sfz files, and multiple MIDI channels. For this reason, NBO instruments that offer multiple articulations have a single sfz file which loads all the articulations, and uses MIDI controller messages (usually "Sound Variation" controller, or CC number 70) to switch articulations. This sfz has the word "full" in the filename. For example, "lp_full.sfz" loads all of the aforementioned LesPaul articulations. To switch between the articulations, you use a "Sound Variation" controller as so:
Sound Variation with value 0. 	Normal sustain, no vibrato.
Sound Variation with value 1. 	Normal sustain, with vibrato.
Sound Variation with value 127. 	Hammer on/off, no vibrato.
Sound Variation with value 126. 	Hammer on/off, with vibrato.
Sound Variation with value 2. 	Muted.
Sound Variation with value 3. 	Harmonic.
Noise articulations are automatically added at random, for added realism.  
Bass All Bass instruments are stereo.
Many of the basses have different styles of playing (ie, articulations). For example, the Fender fingered bass has sustained, hammer on/off, popped, and slapped articulations. Each articulation is available in a separate sfz file. For example, the FenderFinger has 3 sfz files named fender_finger.sfz, fender_popped.sfz, and fender_slapped.sfz for the sustain, popped, and slapped articulations, respectively. (The hammer on/off articulation is included in the sustain articulation).
Files with a short, nondescriptive name, usually a capital letter followed by a number such as S1, S2l, N1, etc, are not to be used directly. They're support files.
Often, you want to switch articulations for a given instrument. In order to switch articulations on-the-fly, you normally need to load the sfz file for each articulation, and set it to a different MIDI channel. When trying to play and switch articulations live, it can be inconvenient to deal with multiple sfz files, and multiple MIDI channels. For this reason, NBO instruments that offer multiple articulations have a single sfz file which loads all the articulations, and uses MIDI controller messages (usually "Sound Variation" controller, or CC number 70) to switch articulations. This sfz has the word "full" in the filename. For example, "fender_finger_full.sfz" loads all of the aforementioned Fender articulations. To switch between the articulations, you use a "Sound Variation" controller as so:
Sound Variation with value 0. 	Normal sustain, no vibrato.
Sound Variation with value 1. 	Normal sustain, with vibrato.
Sound Variation with value 127. 	Hammer on/off, no vibrato.
Sound Variation with value 126. 	Hammer on/off, with vibrato.
Sound Variation with value 2. 	Slapped.
Sound Variation with value 3. 	Popped.
Sound Variation with value 4. 	Muted.
To hear a demo, load the NoBudgetBand/Bass/FenderFinger/fender_finger_full.sfz instrument in LinuxSampler. Then play the funk.mid MIDI file located in NoBudgetBand/Bass/FenderFinger/Demo.
Noise articulations are automatically added at random, for added realism.
For an acoustic (plucked) jazz bass, use the No Budjet Orchestra's solo bass pizzicato (NoBudgetOrch/DoubleBass/SoloBass/bass_pizzi.sfz).  
Orchestral  All Orchestral instruments are stereo.
Many of the instrument sections have an extended note range to accommodate an entire family of instruments. For example, the clarinet ensemble's (NoBudgetOrch/Clarinet/ClarinetSect) note range covers both the alto and bass clarinet range. The trombone ensemble covers both tenor and bass trombone. The following chart lists the sfz file to use for a particular section:
Piccolo	Flute/PiccoloSect/piccolos_full.sfz
Flute, Bass flute	Flute/FluteSect/flutes_full.sfz
Violin, Viola	Violin/ViolinSect/violins_full.sfz
Cello	Cello/CelloSect/cellos_full.sfz
Double bass	DoubleBass/BassSect/basses_full.sfz
Oboe, English horn	Oboe/OboeSect/oboes_full.sfz
Clarinet, Bass clarinet	Clarinet/ClarinetSect/clarinets_full.sfz
Bassoon, Contrabassoon	Bassoon/BassoonSect/bassoons_full.sfz
Trumpet	Trumpet/TrumpetSect/trumpets_full.sfz
Trombone, Bass trombone	Trombone/TromboneSect/trombones_full.sfz
French horn	FrenchHorn/HornSect/horns_full.sfz
Tuba, Bass tuba	Tuba/TubaSect/tubas_full.sfz
There are many solo instruments:
Soprano, alto recorder	Flute/Recorder/recorder_vib.sfz
Flute	Flute/SoloFlute/flute_full.sfz
Pan Flute	Flute/PanFlute/panflute_vib.sfz
Violin I	Violin/SoloViolin1/violin_full.sfz
Violin II	Violin/SoloViolin2/violin2_full.sfz
Viola	Violin/SoloViola/viola_full.sfz
Cello	Cello/SoloCello/cello_full.sfz
Double bass	DoubleBass/SoloBass/bass_full.sfz
Oboe	Oboe/SoloOboe/oboe_full.sfz
Clarinet	Clarinet/SoloClarinet/clarinet_full.sfz
Bassoon	Bassoon/SoloBassoon/bassoon_full.sfz
Trumpet	Trumpet/SoloTrumpet/trumpet_full.sfz
Trombone, Bass trombone	Trombone/SoloTrombone/trombone_full.sfz
French horn	FrenchHorn/SoloHorn/horn_full.sfz
Tuba	Tuba/SoloTuba/tuba_full.sfz
Harpsichord	Harpsichord/harpsichord.sfz
Harp	Harp/harp.sfz
The percussion directory contains many percussion instruments, including tuned percussion such as timpani, marimba, xylophone, etc.
Articulations
Many of the instruments have different styles of playing (ie, articulations). For example, a violin can be played legato (ie, normal playing style), pizzicato, or tremulo. Furthermore, a violin can be played with or without vibrato, and NBO considers these two different articulations. Each articulation is available in a separate sfz file. For example, the solo violin has 3 sfz files named violin.sfz, violin_pizzi.sfz, and violin_tremulo.sfz for the legato, pizzicato, and tremulo articulations, without vibrato. It has 2 more sfz files named violin_vib.sfz and violin_pizzi_vib.sfz for the legato and pizzicato articulations, with vibrato. (A tremulo articulation would not be played with vibrato).
For instruments that normally play one note at a time, you should use the legato mode mappings. These filenames have "legmode" in them (ie, bass_legmode.sfz, cello_legmode.sfz, flute_legmode.sfz, trumpet_legmode.sfz, etc). With legato mode, when you play a note, and then overlap the next note (ie, start the second note before you release the first note) it "smoothes" the transition between the two notes. For a bowed instrument, this simulates the musician playing both notes with a single bow stroke (instead of a separate bow stroke for each note). For wind/brass instruments, this simulates the musician playing both notes with a single breath/tonguing (ie, a slur). Legato mode is useful if you want to make the sampled instrument sound more realistic, by simulating real bowing/breath/tonguing. In music theory terms, it allows you to simulate realistic-sounding "phrasing" for string/wind/brass instruments.
To use legato mode on a midi track, go into the "Piano roll" editor, and overlap any series of notes you want to be played with a single bow stroke (i.e., as a single phrase).
For live performances, physically play the second note before you release the first note. For musicians with limited technique, it may be difficult to control legato mode this way. So I offer 2 additional mappings for 2 alternate methods of controlling legato mode. Filenames that have "legsus" in them (ie, cello_legsus.sfz, flute_legsus.sfz, trumpet_legsus.sfz, etc) control legato mode using MIDI sustain pedal (controller # 64). While the sustain pedal is on, notes are played legato. When the sustain pedal is off, notes are played normally. (To use this properly, you should have the pedal off for the first note of a phrase, and then immediately hold the pedal on while playing the subsequent notes of that phrase). Filenames that have "legped" in them instead use MIDI legato pedal (controller # 68) to control legato mode. Even this may be too difficult for musicians with very limited technique. So I offer the following simple sfz:
<region> sample=Practice more, you lazy sod .wav
There's just one caveat with legato mappings. Due to the way it works, it's limited to single note lines. If you try to play 2 (or more) notes simultaneously, only one of the notes will sound. The others will be immediately cut off. So if you need to play chords, you can't use the legato mappings. Use a regular mapping (ie, bass.sfz, cello.sfz, flute.sfz, trumpet.sfz, etc).
Filenames with "_vib" mean that the instrument has vibrato. So flute_vib_legsus.sfz is a legato mode (using sustain pedal) flute with vibrato. flute_legsus.sfz is without vibrato.
Files with a short, nondescriptive name, usually a capital letter followed by a number such as S1, V2l, R1, etc, are not to be used directly. They're support files.
Full articulations
Often, you want to switch articulations for a given instrument. For example. the No Budget Orchestra's solo violin offers normal sustain with fast or slow bowing as well as with or without vibrato, tremulo with fast or slow bowing, and legato (ie, smooth transition from note to note) with or without vibrato.
In order to switch articulations on-the-fly, you normally need to load the sfz file for each articulation, and set it to a different MIDI channel. When trying to play and switch articulations live, it can be inconvenient to deal with multiple sfz files, and multiple MIDI channels. For this reason, NBO instruments that offer multiple articulations have a single sfz file which loads all the articulations, and uses MIDI controller messages (usually "Sound Variation" controller, or CC number 70) to switch articulations. This sfz has the word "full" in the filename. For example, "violin_full.sfz" loads all of the aforementioned articulations. To switch between the articulations, you use a combination of "Sound Variation" and "Soft pedal" (CC #67) controllers as so:
Sound Variation with value 0.
Soft pedal with value 0. 	Normal sustain, fast bowing, no vibrato.
Sound Variation with value 0.
Soft pedal with value 127. 	Normal sustain, slow bowing, no vibrato.
Sound Variation with value 1.
Soft pedal with value 0. 	Normal sustain, fast bowing, with vibrato.
Sound Variation with value 1.
Soft pedal with value 127. 	Normal sustain, slow bowing, with vibrato.
Sound Variation with value 127.
Soft pedal with value 0. 	Legato, fast bowing, no vibrato.
Sound Variation with value 127.
Soft pedal with value 127. 	Legato, slow bowing, no vibrato.
Sound Variation with value 126.
Soft pedal with value 0. 	Legato, fast bowing, with vibrato.
Sound Variation with value 126.
Soft pedal with value 127. 	Legato, slow bowing, with vibrato.
Sound Variation with value 2.
Soft pedal with value 0. 	Tremulo, fast bowing.
Sound Variation with value 2.
Soft pedal with value 127. 	Tremulo, slow bowing.
Sound Variation with value 3. 	Pizzicato.
The NBO violin section has a "violins_full.sfz" file. It offers the following articulations:
Sound Variation with value 0.
Soft pedal with value 0. 	Normal sustain, fast bowing.
Sound Variation with value 0.
Soft pedal with value 127. 	Normal sustain, slow bowing.
Sound Variation with value 127.
Soft pedal with value 0. 	Legato, fast bowing.
Sound Variation with value 127.
Soft pedal with value 127. 	Legato, slow bowing.
Sound Variation with value 2.
Soft pedal with value 0. 	Tremulo, fast bowing.
Sound Variation with value 2.
Soft pedal with value 127. 	Tremulo, slow bowing.
Sound Variation with value 3. 	Pizzicato.
The file "cellos_full.sfz" does the same for NBO's cello section. As an example, load that sfz (NoBudgetOrch/Cello/CelloSect) in LinuxSampler, and set it to midi channel 15. Play the example midi file cellos_full.mid. First you'll hear a 4 note arpeggio played with normal sustain. Then you'll hear the same arpeggio played pizzicato. Next you'll hear the arpeggio played tremulo. After this you'll hear 4 low g notes played with normal (fast) bowing, followed by the same 4 notes with slow bowing. If you examine the midi events, you'll see how CC's 70 and 67 are used to change articulation.
Mixed sections
The folder named MixedSect contains patches where each patch contains two or more instruments. For example, strings.sfz contains violins mapped to the upper keys, cellos mapped to the middle keys, and double basses mapped to the lower keys. This offers a patch that plays a "strings" sound across the entire piano keyboard.
brass.sfz does the same for brass instruments.